Tag Archives: IPv6

IPv6 over MPLS – 6PE/6VPE

Cisco, IPv6, MPLS, , ,
IPv6 over MPLS

We have a standard MPLS service provider network running with IPv4 IGP, LDP and MP-BGP. Now we want to connect customer’s IPv6 sites over MPLS service provider network. One option is to run IPv6 IGP, LDPv6 (LDP for IPv6 routes) and MP-BGP in service provider network. Currently LDPv6 is in draft stage.

Another approach is to maintain the MPLS network as it stands, but implement mechanisms on the PE routers that allow to transport IPv6 packets as normal labeled packets on the P routers. This is exactly what the 6PE and 6VPE solutions do.

Both 6PE and 6VPE exploit the fact that as long as a packet somehow can be forwarded along an LSP from ingress to egress PE, P routers do not care about anything but the transport label. When using a BGP route in an IPv4 MPLS VPN (or just IPv4 over MPLS), the top label is found by looking at the BGP next hop of the route. The ingress looks at this IPv4 next hop, finds the label associated with it, and by using this label, the packet will be forwarded to the egress PE.

The difference between 6PE and 6VPE is whether the IPv6 routes are in the global routing table or in VRFs. 6PE serves the same role as plain IPv4 over MPLS, and 6VPE is the equivalent of an MPLS VPN.

6PE Design
  • 6PE is defined in RFC4798
  • Service provider network is with IPv4 IGP, LDP and MP-BGP
  • Service provider core (P Routers) is BGP free and not running IPv6
  • PE routers are dual stack, running both IPv4 and IPv6
  • PE routers stores IPv6 routing information in global routing table from all IPv6 customers
6VPE Design
  • 6VPE is defined in RFC4659
  • Service provider network is with IPv4 IGP, LDP and MP-BGP
  • Service provider core is BGP free and not running IPv4
  • PE routers are dual stack, running both IPv4 and IPv6
  • PE routers stores IPv6 routing information in separate VRF for each IPv6 customer, providing MPLS VPN for IPv6

We will use following network topology to configure 6PE and 6VPE.

6PE Configuration
When using 6PE, a CE router is connected to an interface on the PE router, which is in the global IPv6 routing table. There is an MPLS network with BGP, an IGP and LDP between PE routers. The IGP and LDP only needs to be IPv4 capable. However, the BGP session need to be activated for the IPv6 unicast address family to make it possible to advertise IPv6 prefixes from PE to PE. Additionally, BGP needs to attach a label to each IPv6 prefix with the ‘send label’ command. 

R1 - PE1 Router

hostname R1
!
ip cef
ipv6 unicast-routing
ipv6 cef
!
interface Loopback0
 ip address 10.1.0.1 255.255.255.255
 ip ospf 1 area 0
!
interface FastEthernet0/0
 ip address 10.1.13.1 255.255.255.0
 ip ospf network point-to-point
 ip ospf 1 area 0
 mpls ip
!
interface FastEthernet1/0
 no ip address
 ipv6 address 2001:192:168:14::1/64
!
interface FastEthernet1/1
 no ip address
 ipv6 address 2001:172:16:15::1/64
!
router ospf 1
 router-id 10.1.0.1
!
router bgp 100
 bgp router-id 10.1.0.1
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 10.1.0.2 remote-as 100
 neighbor 10.1.0.2 update-source Loopback0
 neighbor 2001:172:16:15::5 remote-as 65005
 neighbor 2001:192:168:14::4 remote-as 65004
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
  redistribute connected
  neighbor 10.1.0.2 activate
  neighbor 10.1.0.2 send-label
  neighbor 2001:172:16:15::5 activate
  neighbor 2001:172:16:15::5 route-map CUST-XYZ out
  neighbor 2001:192:168:14::4 activate
  neighbor 2001:192:168:14::4 route-map CUST-ABC out
 exit-address-family
!
ipv6 prefix-list CUST-ABC seq 5 permit 2001:192::/32 le 64
!
ipv6 prefix-list CUST-XYZ seq 5 permit 2001:172::/32 le 64
!
route-map CUST-XYZ permit 10
 match ipv6 address prefix-list CUST-XYZ
!
route-map CUST-ABC permit 10
 match ipv6 address prefix-list CUST-ABC
!

R2 - PE2 Router

hostname R2
!
no ip domain lookup
ip cef
ipv6 unicast-routing
ipv6 cef
!
interface Loopback0
 ip address 10.1.0.2 255.255.255.255
 ip ospf 1 area 0
!
interface FastEthernet0/0
 ip address 10.1.23.2 255.255.255.0
 ip ospf network point-to-point
 ip ospf 1 area 0
 mpls ip
!
interface FastEthernet1/0
 no ip address
 ipv6 address 2001:192:168:26::2/64
!
interface FastEthernet1/1
 no ip address
 ipv6 address 2001:172:16:27::2/64
!
router ospf 1
 router-id 10.1.0.2
!
router bgp 100
 bgp router-id 10.1.0.2
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 10.1.0.1 remote-as 100
 neighbor 10.1.0.1 update-source Loopback0
 neighbor 2001:172:16:27::7 remote-as 65007
 neighbor 2001:192:168:26::6 remote-as 65006
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
  redistribute connected
  neighbor 10.1.0.1 activate
  neighbor 10.1.0.1 send-label
  neighbor 2001:172:16:27::7 activate
  neighbor 2001:172:16:27::7 route-map CUST-XYZ out
  neighbor 2001:192:168:26::6 activate
  neighbor 2001:192:168:26::6 route-map CUST-ABC out
 exit-address-family
!
ipv6 prefix-list CUST-ABC seq 5 permit 2001:192::/32 le 64
!
ipv6 prefix-list CUST-XYZ seq 5 permit 2001:172::/32 le 64
!
route-map CUST-XYZ permit 10
 match ipv6 address prefix-list CUST-XYZ
!
route-map CUST-ABC permit 10
 match ipv6 address prefix-list CUST-ABC
!

R3 - P Router

hostname R3
!
ip cef
!
interface Loopback0
 ip address 10.1.0.3 255.255.255.255
 ip ospf 1 area 0
!
interface FastEthernet0/0
 ip address 10.1.13.3 255.255.255.0
 ip ospf network point-to-point
 ip ospf 1 area 0
 mpls ip
!
interface FastEthernet0/1
 ip address 10.1.23.3 255.255.255.0
 ip ospf network point-to-point
 ip ospf 1 area 0
 mpls ip
!
router ospf 1
 router-id 10.1.0.3
!

R4 - Customer ABC Site 1

hostname R4
!
ipv6 unicast-routing
ipv6 cef
!
interface FastEthernet0/0
 no ip address
 ipv6 address 2001:192:168:14::4/64
!
interface FastEthernet0/1
 no ip address
 ipv6 address 2001:192:168:4::4/64
!
router bgp 65004
 bgp router-id 4.4.4.4
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 2001:192:168:14::1 remote-as 100
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
  network 2001:192:168:4::/64
  neighbor 2001:192:168:14::1 activate
 exit-address-family
!

R5 - Customer XYZ Site 1

hostname R5
!
ipv6 unicast-routing
ipv6 cef
!
interface FastEthernet0/0
 no ip address
 ipv6 address 2001:172:16:15::5/64
!
interface FastEthernet0/1
 no ip address
 ipv6 address 2001:172:16:5::5/64
!
router bgp 65005
 bgp router-id 5.5.5.5
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 2001:172:16:15::1 remote-as 100
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
  network 2001:172:16:5::/64
  neighbor 2001:172:16:15::1 activate
 exit-address-family
!

R6 - Customer ABC Site 2

hostname R6
!
ipv6 unicast-routing
ipv6 cef
!
interface FastEthernet0/0
 no ip address
 ipv6 address 2001:192:168:26::6/64
!
interface FastEthernet0/1
 no ip address
 ipv6 address 2001:192:168:6::6/64
!
router bgp 65006
 bgp router-id 6.6.6.6
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 2001:192:168:26::2 remote-as 100
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
  network 2001:192:168:6::/64
  neighbor 2001:192:168:26::2 activate
 exit-address-family
!

R7 - Customer XYZ Site 2

hostname R7
!
ipv6 unicast-routing
ipv6 cef
!
interface FastEthernet0/0
 no ip address
 ipv6 address 2001:172:16:27::7/64
!
interface FastEthernet0/1
 no ip address
 ipv6 address 2001:172:16:7::7/64
!
router bgp 65007
 bgp router-id 7.7.7.7
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 2001:172:16:27::2 remote-as 100
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
  network 2001:172:16:7::/64
  neighbor 2001:172:16:27::2 activate
 exit-address-family
!
Verification
PE Router BGP Peering

!! -- PE1 (R1) has IPv6 BGP+Label peering with PE2 (R2) -- !!
!! -- PE1 (R1) has IPv6 BGP peering with CE4 (R4) -- !!
!! -- PE1 (R1) has IPv6 BGP peering with CE5 (R5) -- !!

R1#show bgp ipv6 unicast summary 
BGP router identifier 10.1.0.1, local AS number 100
BGP table version is 9, main routing table version 9
8 network entries using 1376 bytes of memory
8 path entries using 704 bytes of memory
6/6 BGP path/bestpath attribute entries using 816 bytes of memory
4 BGP AS-PATH entries using 96 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 2992 total bytes of memory
BGP activity 8/0 prefixes, 8/0 paths, scan interval 60 secs

Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
10.1.0.2        4          100     179     181        9    0    0 02:21:48        4
2001:172:16:15::5
                4        65005     161     178        9    0    0 02:22:05        1
2001:192:168:14::4
                4        65004     163     176        9    0    0 02:22:03        1

The PE1 router will receive IPv6 routes with a label and a next hop of ::FFFF:10.1.0.2. This next hop is an “IPv4-mapped IPv6 address” and it tells the router that if it were to use that IPv6 BGP route, it should use the transport label for the IPv4 address 10.1.0.2.

Similarly, PE2 router will receive IPv6 routes with a label and a next hop of ::FFFF:10.1.0.1.

R1#show bgp ipv6 unicast
BGP table version is 9, local router ID is 10.1.0.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, 
              x best-external, a additional-path, c RIB-compressed, 
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *>  2001:172:16:5::/64
                       2001:172:16:15::5
                                                0             0 65005 i
 *>i 2001:172:16:7::/64
                       ::FFFF:10.1.0.2          0    100      0 65007 i
 *>  2001:172:16:15::/64
                       ::                       0         32768 ?
 *>i 2001:172:16:27::/64
                       ::FFFF:10.1.0.2          0    100      0 ?
 *>  2001:192:168:4::/64
                       2001:192:168:14::4
                                                0             0 65004 i
 *>i 2001:192:168:6::/64
                       ::FFFF:10.1.0.2          0    100      0 65006 i
 *>  2001:192:168:14::/64
                       ::                       0         32768 ?
 *>i 2001:192:168:26::/64
                       ::FFFF:10.1.0.2          0    100      0 ?

R2#show bgp ipv6 unicast summary
BGP router identifier 10.1.0.2, local AS number 100
BGP table version is 9, main routing table version 9
8 network entries using 1376 bytes of memory
8 path entries using 704 bytes of memory
6/6 BGP path/bestpath attribute entries using 816 bytes of memory
4 BGP AS-PATH entries using 96 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 2992 total bytes of memory
BGP activity 8/0 prefixes, 8/0 paths, scan interval 60 secs

Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
10.1.0.1        4          100     183     181        9    0    0 02:23:38        4
2001:172:16:27::7
                4        65007     165     176        9    0    0 02:23:51        1
2001:192:168:26::6
                4        65006     163     175        9    0    0 02:23:50        1

R2#show bgp ipv6 unicast        
BGP table version is 9, local router ID is 10.1.0.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, 
              x best-external, a additional-path, c RIB-compressed, 
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *>i 2001:172:16:5::/64
                       ::FFFF:10.1.0.1          0    100      0 65005 i
 *>  2001:172:16:7::/64
                       2001:172:16:27::7
                                                0             0 65007 i
 *>i 2001:172:16:15::/64
                       ::FFFF:10.1.0.1          0    100      0 ?
 *>  2001:172:16:27::/64
                       ::                       0         32768 ?
 *>i 2001:192:168:4::/64
                       ::FFFF:10.1.0.1          0    100      0 65004 i
 *>  2001:192:168:6::/64
                       2001:192:168:26::6
                                                0             0 65006 i
 *>i 2001:192:168:14::/64
                       ::FFFF:10.1.0.1          0    100      0 ?
 *>  2001:192:168:26::/64
                       ::                       0         32768 ?

!! -- Verify BGP Label Assignments -- !!

R1#show bgp ipv6 unicast labels 
   Network          Next Hop      In label/Out label
   2001:172:16:5::/64
                    2001:172:16:15::5
                                    19/nolabel
   2001:172:16:7::/64
                    ::FFFF:10.1.0.2 nolabel/19
   2001:172:16:15::/64
                    ::              20/nolabel
   2001:172:16:27::/64
                    ::FFFF:10.1.0.2 nolabel/20
   2001:192:168:4::/64
                    2001:192:168:14::4
                                    22/nolabel
   2001:192:168:6::/64
                    ::FFFF:10.1.0.2 nolabel/22
   2001:192:168:14::/64
                    ::              21/nolabel
   2001:192:168:26::/64
                    ::FFFF:10.1.0.2 nolabel/21

R2#show bgp ipv6 unicast labels
   Network          Next Hop      In label/Out label
   2001:172:16:5::/64
                    ::FFFF:10.1.0.1 nolabel/19
   2001:172:16:7::/64
                    2001:172:16:27::7
                                    19/nolabel
   2001:172:16:15::/64
                    ::FFFF:10.1.0.1 nolabel/20
   2001:172:16:27::/64
                    ::              20/nolabel
   2001:192:168:4::/64
                    ::FFFF:10.1.0.1 nolabel/22
   2001:192:168:6::/64
                    2001:192:168:26::6
                                    22/nolabel
   2001:192:168:14::/64
                    ::FFFF:10.1.0.1 nolabel/21
   2001:192:168:26::/64
                    ::              21/nolabel

!! -- Customer ABC Site-2 LAN IPv6 network reachability from PE1-R1 via MPLS path -- !!

R1#show bgp ipv6 unicast 2001:192:168:6::/64
BGP routing table entry for 2001:192:168:6::/64, version 9
Paths: (1 available, best #1, table default)
  Advertised to update-groups:
     3         
  Refresh Epoch 5
  65006
    ::FFFF:10.1.0.2 (metric 3) from 10.1.0.2 (10.1.0.2)
      Origin IGP, metric 0, localpref 100, valid, internal, best
      mpls labels in/out nolabel/22
R1#sh ipv6 cef 2001:192:168:6::/64 detail 
2001:192:168:6::/64, epoch 0, flags rib defined all labels
  recursive via 10.1.0.2 label 22
    nexthop 10.1.13.3 FastEthernet0/0 label 16

!! -- Ping/Traceroute from R4 Customer ABC Site-1 to Site-2 -- !!
!! -- via MPLS provider network -- !!

R4#show ipv6 route
IPv6 Routing Table - default - 7 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
       H - NHRP, I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea
       IS - ISIS summary, D - EIGRP, EX - EIGRP external, NM - NEMO
       ND - ND Default, NDp - ND Prefix, DCE - Destination, NDr - Redirect
       O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
C   2001:192:168:4::/64 [0/0]
     via FastEthernet0/1, directly connected
L   2001:192:168:4::4/128 [0/0]
     via FastEthernet0/1, receive
B   2001:192:168:6::/64 [20/0]
     via FE80::C803:31FF:FE5C:1C, FastEthernet0/0
C   2001:192:168:14::/64 [0/0]
     via FastEthernet0/0, directly connected
L   2001:192:168:14::4/128 [0/0]
     via FastEthernet0/0, receive
B   2001:192:168:26::/64 [20/0]
     via FE80::C803:31FF:FE5C:1C, FastEthernet0/0
L   FF00::/8 [0/0]
     via Null0, receive


R4#ping 2001:192:168:6::6 source 2001:192:168:4::4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:192:168:6::6, timeout is 2 seconds:
Packet sent with a source address of 2001:192:168:4::4
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 76/93/104 ms

R4#traceroute 
Protocol [ip]: ipv6
Target IPv6 address: 2001:192:168:6::6
Source address: 2001:192:168:4::4
Insert source routing header? [no]: 
Numeric display? [no]: 
Timeout in seconds [3]: 
Probe count [3]: 
Minimum Time to Live [1]: 
Maximum Time to Live [30]: 
Priority [0]: 
Port Number [0]: 
Type escape sequence to abort.
Tracing the route to 2001:192:168:6::6

  1 2001:192:168:14::1 [AS 100] 72 msec 44 msec 24 msec
  2 ::FFFF:10.1.13.3 [MPLS: Labels 16/22 Exp 0] 92 msec 88 msec 88 msec
  3 2001:192:168:26::2 [AS 100] [MPLS: Label 22 Exp 0] 76 msec 56 msec 68 msec
  4 2001:192:168:26::6 [AS 100] 92 msec 96 msec 88 msec
6VPE Configuration
!! -- Only PE routers configuration will be changed -- !!
!! -- CE facing interface on PE router will be in a VRF -- !!

R1 - PE1 Router

hostname R1
!
vrf definition CUST-ABC
 rd 100:1
 !
 address-family ipv6
  route-target export 100:1
  route-target import 100:1
 exit-address-family
!
vrf definition CUST-XYZ
 rd 100:2
 !
 address-family ipv6
  route-target export 100:2
  route-target import 100:2
 exit-address-family
!
ip cef
ipv6 unicast-routing
ipv6 cef
!
interface Loopback0
 ip address 10.1.0.1 255.255.255.255
 ip ospf 1 area 0
!
interface FastEthernet0/0
 ip address 10.1.13.1 255.255.255.0
 ip ospf network point-to-point
 ip ospf 1 area 0
 mpls ip
!
interface FastEthernet1/0
 vrf forwarding CUST-ABC
 no ip address
 ipv6 address 2001:192:168:14::1/64
!
interface FastEthernet1/1
 vrf forwarding CUST-XYZ
 no ip address
 ipv6 address 2001:172:16:15::1/64
!
router ospf 1
 router-id 10.1.0.1
!
router bgp 100
 bgp router-id 10.1.0.1
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 10.1.0.2 remote-as 100
 neighbor 10.1.0.2 update-source Loopback0
 !
 address-family ipv4
 exit-address-family
 !
 address-family vpnv6
  neighbor 10.1.0.2 activate
  neighbor 10.1.0.2 send-community extended
 exit-address-family
 !
 address-family ipv6 vrf CUST-ABC
  redistribute connected
  neighbor 2001:192:168:14::4 remote-as 65004
  neighbor 2001:192:168:14::4 activate
 exit-address-family
 !
 address-family ipv6 vrf CUST-XYZ
  redistribute connected
  neighbor 2001:172:16:15::5 remote-as 65005
  neighbor 2001:172:16:15::5 activate
 exit-address-family
!

R2 - PE2 Router

hostname R2
!
vrf definition CUST-ABC
 rd 100:1
 !
 address-family ipv6
  route-target export 100:1
  route-target import 100:1
 exit-address-family
!
vrf definition CUST-XYZ
 rd 100:2
 !
 address-family ipv6
  route-target export 100:2
  route-target import 100:2
 exit-address-family
!
ip cef
ipv6 unicast-routing
ipv6 cef
!
interface Loopback0
 ip address 10.1.0.2 255.255.255.255
 ip ospf 1 area 0
!
interface FastEthernet0/0
 ip address 10.1.23.2 255.255.255.0
 ip ospf network point-to-point
 ip ospf 1 area 0
 mpls ip
!
interface FastEthernet1/0
 vrf forwarding CUST-ABC
 no ip address
 ipv6 address 2001:192:168:26::2/64
!
interface FastEthernet1/1
 vrf forwarding CUST-XYZ
 no ip address
 ipv6 address 2001:172:16:27::2/64
!
router ospf 1
 router-id 10.1.0.2
!
router bgp 100
 bgp router-id 10.1.0.2
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 10.1.0.1 remote-as 100
 neighbor 10.1.0.1 update-source Loopback0
 !
 address-family ipv4
 exit-address-family
 !
 address-family vpnv6
  neighbor 10.1.0.1 activate
  neighbor 10.1.0.1 send-community extended
 exit-address-family
 !
 address-family ipv6 vrf CUST-ABC
  redistribute connected
  neighbor 2001:192:168:26::6 remote-as 65006
  neighbor 2001:192:168:26::6 activate
 exit-address-family
 !
 address-family ipv6 vrf CUST-XYZ
  redistribute connected
  neighbor 2001:172:16:27::7 remote-as 65007
  neighbor 2001:172:16:27::7 activate
 exit-address-family
!
Verification
!! -- VRF status on PE Routers -- !!

R1#show vrf 
  Name                             Default RD          Protocols   Interfaces
  CUST-ABC                         100:1               ipv6        Fa1/0
  CUST-XYZ                         100:2               ipv6        Fa1/1

R2#show vrf 
  Name                             Default RD          Protocols   Interfaces
  CUST-ABC                         100:1               ipv6        Fa1/0
  CUST-XYZ                         100:2               ipv6        Fa1/1

!! -- BGP Peering on PE Routers -- !!
R1#show bgp vpnv6 unicast all summary 
BGP router identifier 10.1.0.1, local AS number 100
BGP table version is 13, main routing table version 13
8 network entries using 1536 bytes of memory
8 path entries using 736 bytes of memory
10/8 BGP path/bestpath attribute entries using 1440 bytes of memory
4 BGP AS-PATH entries using 96 bytes of memory
2 BGP extended community entries using 48 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 3856 total bytes of memory
BGP activity 16/8 prefixes, 16/8 paths, scan interval 60 secs

Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
10.1.0.2        4          100      28      29       13    0    0 00:19:42        4
2001:172:16:15::5
                4        65005      29      30       13    0    0 00:22:35        1
2001:192:168:14::4
                4        65004      30      32       13    0    0 00:23:04        1

R2#show bgp vpnv6 unicast all summary 
BGP router identifier 10.1.0.2, local AS number 100
BGP table version is 13, main routing table version 13
8 network entries using 1536 bytes of memory
8 path entries using 736 bytes of memory
10/8 BGP path/bestpath attribute entries using 1440 bytes of memory
4 BGP AS-PATH entries using 96 bytes of memory
2 BGP extended community entries using 48 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 3856 total bytes of memory
BGP activity 8/0 prefixes, 8/0 paths, scan interval 60 secs

Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
10.1.0.1        4          100      30      28       13    0    0 00:19:57        4
2001:172:16:27::7
                4        65007      25      28       13    0    0 00:18:58        1
2001:192:168:26::6
                4        65006      26      27       13    0    0 00:19:23        1

!! -- BGP Table on PE Routers -- !!

R1#show bgp vpnv6 unicast all
BGP table version is 13, local router ID is 10.1.0.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, 
              x best-external, a additional-path, c RIB-compressed, 
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 100:1 (default for vrf CUST-ABC)
 *>  2001:192:168:4::/64
                       2001:192:168:14::4
                                                0             0 65004 i
 *>i 2001:192:168:6::/64
                       ::FFFF:10.1.0.2          0    100      0 65006 i
 *>  2001:192:168:14::/64
                       ::                       0         32768 ?
 *>i 2001:192:168:26::/64
                       ::FFFF:10.1.0.2          0    100      0 ?
Route Distinguisher: 100:2 (default for vrf CUST-XYZ)
 *>  2001:172:16:5::/64
                       2001:172:16:15::5
                                                0             0 65005 i
 *>i 2001:172:16:7::/64
                       ::FFFF:10.1.0.2          0    100      0 65007 i
 *>  2001:172:16:15::/64
                       ::                       0         32768 ?
 *>i 2001:172:16:27::/64
                       ::FFFF:10.1.0.2          0    100      0 ?

R2#show bgp vpnv6 unicast all
BGP table version is 13, local router ID is 10.1.0.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, 
              x best-external, a additional-path, c RIB-compressed, 
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 100:1 (default for vrf CUST-ABC)
 *>i 2001:192:168:4::/64
                       ::FFFF:10.1.0.1          0    100      0 65004 i
 *>  2001:192:168:6::/64
                       2001:192:168:26::6
                                                0             0 65006 i
 *>i 2001:192:168:14::/64
                       ::FFFF:10.1.0.1          0    100      0 ?
 *>  2001:192:168:26::/64
                       ::                       0         32768 ?
Route Distinguisher: 100:2 (default for vrf CUST-XYZ)
 *>i 2001:172:16:5::/64
                       ::FFFF:10.1.0.1          0    100      0 65005 i
 *>  2001:172:16:7::/64
                       2001:172:16:27::7
                                                0             0 65007 i
 *>i 2001:172:16:15::/64
                       ::FFFF:10.1.0.1          0    100      0 ?
 *>  2001:172:16:27::/64
                       ::                       0         32768 ?

!! -- Customer IPv6 routes are not in Global RIB -- !!

R1#show ipv6 route
IPv6 Routing Table - default - 1 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
       H - NHRP, I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea
       IS - ISIS summary, D - EIGRP, EX - EIGRP external, NM - NEMO
       ND - ND Default, NDp - ND Prefix, DCE - Destination, NDr - Redirect
       O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
L   FF00::/8 [0/0]
     via Null0, receive

R2#show ipv6 route
IPv6 Routing Table - default - 1 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
       H - NHRP, I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea
       IS - ISIS summary, D - EIGRP, EX - EIGRP external, NM - NEMO
       ND - ND Default, NDp - ND Prefix, DCE - Destination, NDr - Redirect
       O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
L   FF00::/8 [0/0]
     via Null0, receive

!! -- MPLS VPN Labels on PE Routers -- !!

R1#sh mpls forwarding-table vrf CUST-ABC
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop    
Label      Label      or Tunnel Id     Switched      interface              
23         No Label   2001:192:168:14::/64[V]   \
                                       0             aggregate/CUST-ABC 
24         No Label   2001:192:168:4::/64[V]   \
                                       1922          Fa1/0      FE80::C805:19FF:FEAC:8

R1#sh mpls forwarding-table vrf CUST-XYZ
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop    
Label      Label      or Tunnel Id     Switched      interface              
25         No Label   2001:172:16:15::/64[V]   \
                                       0             aggregate/CUST-XYZ 
26         No Label   2001:172:16:5::/64[V]   \
                                       0             Fa1/1      FE80::C800:17FF:FE58:8

R2#sh mpls forwarding-table vrf CUST-ABC
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop    
Label      Label      or Tunnel Id     Switched      interface              
19         No Label   2001:192:168:26::/64[V]   \
                                       0             aggregate/CUST-ABC 
20         No Label   2001:192:168:6::/64[V]   \
                                       1374          Fa1/0      FE80::C801:17FF:FE58:8
  
R2#sh mpls forwarding-table vrf CUST-XYZ
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop    
Label      Label      or Tunnel Id     Switched      interface              
21         No Label   2001:172:16:7::/64[V]   \
                                       0             Fa1/1      FE80::C802:2BFF:FEF0:8
22         No Label   2001:172:16:27::/64[V]   \
                                       0             aggregate/CUST-XYZ 

!! -- Customer ABC Site-2 LAN IPv6 network reachability from PE1 -- !!

R1#show bgp vpnv6 unicast all 2001:192:168:6::/64        
BGP routing table entry for [100:1]2001:192:168:6::/64, version 7
Paths: (1 available, best #1, table CUST-ABC)
  Advertised to update-groups:
     1         
  Refresh Epoch 1
  65006
    ::FFFF:10.1.0.2 (metric 3) from 10.1.0.2 (10.1.0.2)
      Origin IGP, metric 0, localpref 100, valid, internal, best
      Extended Community: RT:100:1
      mpls labels in/out nolabel/20   <<<<< VPN Label

R1#show ipv6 cef vrf CUST-ABC 2001:192:168:6::/64 detail 
2001:192:168:6::/64, epoch 0, flags rib defined all labels
  recursive via 10.1.0.2 label 20    
    nexthop 10.1.13.3 FastEthernet0/0 label 16   <<<<< Transport Label

!! -- Ping/Traceroute from Customer ABC Site 1 to Site 2 LAN --!!

R4#ping 2001:192:168:6::6 source 2001:192:168:4::4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:192:168:6::6, timeout is 2 seconds:
Packet sent with a source address of 2001:192:168:4::4
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 112/129/136 ms

R4#traceroute 
Protocol [ip]: ipv6
Target IPv6 address: 2001:192:168:6::6
Source address: 2001:192:168:4::4
Insert source routing header? [no]: 
Numeric display? [no]: 
Timeout in seconds [3]: 
Probe count [3]: 
Minimum Time to Live [1]: 
Maximum Time to Live [30]: 
Priority [0]: 
Port Number [0]: 
Type escape sequence to abort.
Tracing the route to 2001:192:168:6::6

  1 2001:192:168:14::1 [AS 100] 44 msec 40 msec 36 msec
  2 ::FFFF:10.1.13.3 [MPLS: Labels 16/20 Exp 0] 120 msec 136 msec 132 msec
  3  * 
    2001:192:168:26::2 108 msec 104 msec
  4 2001:192:168:26::6 [AS 100] 136 msec 128 msec 132 msec

*VPN Label = 20
*Transport Label = 16

 

RIPng for IPv6 Routing

Cisco, IPv6, RIP, , ,

RIPng (Routing Information Protocol Next Generation) defined in RFC 2080 is an extension of RIPv2 for support of IPv6. RIP is a distance vector routing protocol.

We will not talk much about how RIP and distance vector algorithm works. We will demonstrate how it can be configured for IPv6 routing.

RIPng Messaging

There are two basic RIPng message types, RIP Request and RIP Response, which are exchanged using the User Datagram Protocol (UDP) port number 521.

RIP Request messages are sent to UDP destination port 521. They may have a source port of 521 or may use an ephemeral port number.

RIP Response messages sent in reply to an RIP Request are sent with a source port of 521, and a destination port equal to whatever source port the RIP Request used.

Unsolicited RIP Response messages (sent on a routine basis and not in response to a request) are sent with both the source and destination ports set to 521.

Here is the network topology for our discussion:

ripng

We will discuss following topics:

  1. RIPng configuration
  2. RIPng Route Metric Manipulation
  3. RIPng Route Aggregation/Summarization
  4. RIPng Default Route
  5. RIPng Route Filter
RIPng Configuration
R1

!! Enable IPv6 Routing globally !!
ipv6 unicast-routing
!
!! Enable RIPng at interface level !!
!! ipv6 rip [pid] enable, RIPV6 is a process ID used here !!
!
interface Loopback0
 ipv6 address 2001::1/128
 ipv6 rip RIPV6 enable
!
interface GigabitEthernet0/0
 ipv6 address 2001:1:2:14::1/64
 ipv6 rip RIPV6 enable
!
interface FastEthernet1/0
 ipv6 address 2001:1:2:13::1/64
 ipv6 rip RIPV6 enable

R4

ipv6 unicast-routing
!
interface Loopback0
 ipv6 address 2001::4/128
 ipv6 rip RIPV6 enable
!
interface GigabitEthernet0/0
 ipv6 address 2001:1:2:14::4/64
 ipv6 rip RIPV6 enable
!
interface GigabitEthernet1/0
 ipv6 address 2001:1:2:34::4/64
 ipv6 rip RIPV6 enable


R3

ipv6 unicast-routing
!
interface Loopback0
 ipv6 address 2001::3/128
 ipv6 rip RIPV6 enable
!
interface GigabitEthernet0/0
 ipv6 address 2001:1:2:34::3/64
 ipv6 rip RIPV6 enable
!
interface FastEthernet1/0
 ipv6 address 2001:1:2:13::3/64
 ipv6 rip RIPV6 enable
!
interface FastEthernet1/1
 ipv6 address 2001:1:2:23::3/64
 ipv6 rip RIPV6 enable
!
 
R2

ipv6 unicast-routing
!
interface Loopback0
 ipv6 address 2001::2/128
 ipv6 rip RIPV6 enable
!
interface FastEthernet0/0
 ipv6 address 2001:1:2:23::2/64
 ipv6 rip RIPV6 enable
Verification & Testing:
R1#sh ipv6 protocols
IPv6 Routing Protocol is "connected"
IPv6 Routing Protocol is "ND"
IPv6 Routing Protocol is "rip RIPV6"
  Interfaces:
    FastEthernet1/0
    GigabitEthernet0/0
    Loopback0
  Redistribution:
    None

R1#show ipv6 rip
RIP process "RIPV6", port 521, multicast-group FF02::9, pid 276
     Administrative distance is 120. Maximum paths is 16
     Updates every 30 seconds, expire after 180
     Holddown lasts 0 seconds, garbage collect after 120
     Split horizon is on; poison reverse is off
     Default routes are not generated
     Periodic updates 45, trigger updates 3
     Full Advertisement 1, Delayed Events 0
  Interfaces:
    FastEthernet1/0
    GigabitEthernet0/0
    Loopback0
  Redistribution:
    None

R1#show ipv6 route rip
IPv6 Routing Table - default - 11 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, R - RIP, H - NHRP, I1 - ISIS L1
       I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
       EX - EIGRP external, ND - ND Default, NDp - ND Prefix, DCE - Destination
       NDr - Redirect, O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1
       OE2 - OSPF ext 2, ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
R   2001::2/128 [120/3]
     via FE80::C803:21FF:FE78:1C, FastEthernet1/0
R   2001::3/128 [120/2]
     via FE80::C803:21FF:FE78:1C, FastEthernet1/0
R   2001::4/128 [120/2]
     via FE80::C802:21FF:FE78:8, GigabitEthernet0/0
R   2001:1:2:23::/64 [120/2]
     via FE80::C803:21FF:FE78:1C, FastEthernet1/0
R   2001:1:2:34::/64 [120/2]
     via FE80::C802:21FF:FE78:8, GigabitEthernet0/0
     via FE80::C803:21FF:FE78:1C, FastEthernet1/0

!! Routing for Loopback interface of R2 !!
R1#show ipv6 route 2001::2
Routing entry for 2001::2/128
  Known via "rip RIPV6", distance 120, metric 3
  Route count is 1/1, share count 0
  Routing paths:
    FE80::C803:21FF:FE78:1C, FastEthernet1/0
      Last updated 00:23:15 ago
!! Routing entry is known via RIP process RIPV6, administrative distance is 120 and metric(hop count) is 3. Next-Hop is link-local IP (FE80::C803:21FF:FE78:1C) of neighbor router interface which is connected via FastEthernet1/0. !!
R3#sh ipv6 int f1/0
FastEthernet1/0 is up, line protocol is up
  IPv6 is enabled, link-local address is FE80::C803:21FF:FE78:1C

R1#ping 2001::2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001::2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/82/136 ms

R1#traceroute 2001::2
Type escape sequence to abort.
Tracing the route to 2001::2

  1 2001:1:2:13::3 32 msec 56 msec 24 msec
  2 2001:1:2:23::2 60 msec 64 msec 84 msec

Similar test can be done on other routers to verify IPv6 routing.

R4#sh ipv6 route rip
IPv6 Routing Table - default - 11 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, R - RIP, H - NHRP, I1 - ISIS L1
       I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
       EX - EIGRP external, ND - ND Default, NDp - ND Prefix, DCE - Destination
       NDr - Redirect, O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1
       OE2 - OSPF ext 2, ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
R   2001::1/128 [120/2]
     via FE80::C800:27FF:FE54:8, GigabitEthernet0/0
R   2001::2/128 [120/3]
     via FE80::C803:21FF:FE78:8, GigabitEthernet1/0
R   2001::3/128 [120/2]
     via FE80::C803:21FF:FE78:8, GigabitEthernet1/0
R   2001:1:2:13::/64 [120/2]
     via FE80::C803:21FF:FE78:8, GigabitEthernet1/0
     via FE80::C800:27FF:FE54:8, GigabitEthernet0/0
R   2001:1:2:23::/64 [120/2]
     via FE80::C803:21FF:FE78:8, GigabitEthernet1/0

R3#show ipv6 route rip
IPv6 Routing Table - default - 12 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, R - RIP, H - NHRP, I1 - ISIS L1
       I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
       EX - EIGRP external, ND - ND Default, NDp - ND Prefix, DCE - Destination
       NDr - Redirect, O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1
       OE2 - OSPF ext 2, ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
R   2001::1/128 [120/2]
     via FE80::C800:27FF:FE54:1C, FastEthernet1/0
R   2001::2/128 [120/2]
     via FE80::C801:27FF:FE54:8, FastEthernet1/1
R   2001::4/128 [120/2]
     via FE80::C802:21FF:FE78:1C, GigabitEthernet0/0
R   2001:1:2:14::/64 [120/2]
     via FE80::C802:21FF:FE78:1C, GigabitEthernet0/0
     via FE80::C800:27FF:FE54:1C, FastEthernet1/0


R2#show ipv6 route rip
IPv6 Routing Table - default - 10 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, R - RIP, H - NHRP, I1 - ISIS L1
       I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
       EX - EIGRP external, ND - ND Default, NDp - ND Prefix, DCE - Destination
       NDr - Redirect, O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1
       OE2 - OSPF ext 2, ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
R   2001::1/128 [120/3]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001::3/128 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001::4/128 [120/3]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001:1:2:13::/64 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001:1:2:14::/64 [120/3]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001:1:2:34::/64 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0

R2#ping 2001::1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001::1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/80/120 ms
R2#ping 2001::3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001::3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 24/41/56 ms
R2#ping 2001::4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001::4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/58/80 ms
RIPng Route Metric Manipulation

As we see in above output the traffic from R1 to R3/R2 is going via R3 based on the lowest metric(hop-count). We want to go it via R4 (i.e, R1 -> R4 -> R3 -> R2). We can do it by increment the metric on link between R1 and R3. This feature is called metric-offset.

Routing before metric-offset

R1#show ipv6 route rip
<snip>
R   2001::2/128 [120/3]
     via FE80::C803:21FF:FE78:1C, FastEthernet1/0
R   2001::3/128 [120/2]
     via FE80::C803:21FF:FE78:1C, FastEthernet1/0
R   2001::4/128 [120/2]
     via FE80::C802:21FF:FE78:8, GigabitEthernet0/0
R   2001:1:2:23::/64 [120/2]
     via FE80::C803:21FF:FE78:1C, FastEthernet1/0
R   2001:1:2:34::/64 [120/2]
     via FE80::C802:21FF:FE78:8, GigabitEthernet0/0
     via FE80::C803:21FF:FE78:1C, FastEthernet1/0

R3#show ipv6 route rip
<snip>
R   2001::1/128 [120/2]
     via FE80::C800:27FF:FE54:1C, FastEthernet1/0
R   2001::2/128 [120/2]
     via FE80::C801:27FF:FE54:8, FastEthernet1/1
R   2001::4/128 [120/2]
     via FE80::C802:21FF:FE78:1C, GigabitEthernet0/0
R   2001:1:2:14::/64 [120/2]
     via FE80::C802:21FF:FE78:1C, GigabitEthernet0/0
     via FE80::C800:27FF:FE54:1C, FastEthernet1/0

Metric-offset configuration

R1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R1(config)#interface FastEthernet1/0
R1(config-if)# ipv6 rip RIPV6 metric-offset 3
R1(config-if)#end

R3#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R3(config)#interface FastEthernet1/0
R3(config-if)#ipv6 rip RIPV6 metric-offset 3
R3(config-if)#end

Routing after metric-offset

!! Metric for all routes learned via Fa1/0 has been incremented by 3 and routes via Gig0/0 has lowest metric and best path in routing table.!!

R1#show ipv6 route rip
<snip>
R   2001::2/128 [120/4]
     via FE80::C802:21FF:FE78:8, GigabitEthernet0/0
R   2001::3/128 [120/3]
     via FE80::C802:21FF:FE78:8, GigabitEthernet0/0
R   2001::4/128 [120/2]
     via FE80::C802:21FF:FE78:8, GigabitEthernet0/0
R   2001:1:2:23::/64 [120/3]
     via FE80::C802:21FF:FE78:8, GigabitEthernet0/0
R   2001:1:2:34::/64 [120/2]
     via FE80::C802:21FF:FE78:8, GigabitEthernet0/0

R1#ping 2001::2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001::2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 48/60/80 ms

R1#traceroute 2001::2
Type escape sequence to abort.
Tracing the route to 2001::2

  1 2001:1:2:14::4 28 msec 36 msec 28 msec  <<<< R4
  2 2001:1:2:34::3 16 msec 76 msec 32 msec  <<<< R3
  3 2001:1:2:23::2 76 msec 68 msec 60 msec  <<<< R2


R3#show ipv6 route rip
<snip>
R   2001::1/128 [120/3]
     via FE80::C802:21FF:FE78:1C, GigabitEthernet0/0
R   2001::2/128 [120/2]
     via FE80::C801:27FF:FE54:8, FastEthernet1/1
R   2001::4/128 [120/2]
     via FE80::C802:21FF:FE78:1C, GigabitEthernet0/0
R   2001:1:2:14::/64 [120/2]
     via FE80::C802:21FF:FE78:1C, GigabitEthernet0/0

R3#ping 2001::1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001::1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/25/32 ms

R3#traceroute 2001::1
Type escape sequence to abort.
Tracing the route to 2001::1

  1 2001:1:2:34::4 24 msec 36 msec 16 msec  <<<< R4
  2 2001:1:2:14::1 60 msec 16 msec 28 msec  <<<< R1
RIPng Route Aggregation/Summarization

We want to aggregate following routes on R3 which are received from R4 and R1 and advertise summary route  to R2.

2001:1:2:34::/64
2001:1:2:14::/64
2001:1:2:13::/64

Summary route – These 3 routes has first 48 bits common (2001:1:2), so we can aggregate as follows

2001:1:2::/48

R2 routing table before route aggregation on R3

R2#show ipv6 route rip
<snip>
R   2001::1/128 [120/4]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001::3/128 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001::4/128 [120/3]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001:1:2:13::/64 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001:1:2:14::/64 [120/3]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001:1:2:34::/64 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0

Route aggregation configuration on R3

R3#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R3(config)#interface FastEthernet1/1
R3(config-if)#ipv6 rip RIPV6 summary-address 2001:1:2::/48
R3(config-if)#end


R2 routing table after route aggregation on R3

R2#show ipv6 route rip
<snip>
R   2001::1/128 [120/4]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001::3/128 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001::4/128 [120/3]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001:1:2::/48 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
RIPng Default Route

We want to advertise a default route to R2 from R3 so that R2 can send traffic for any unknown prefix to R3.

R2 Before default route configuration

R2#show ipv6 route ::/0
% Route not found

Default-route configuration on R3

R3#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R3(config)#interface FastEthernet1/1
R3(config-if)#ipv6 rip RIPV6 default-information originate
R3(config-if)#end

R2 after default route configuration

R2#show ipv6 route ::/0
Routing entry for ::/0
  Known via "rip RIPV6", distance 120, metric 2
  Route count is 1/1, share count 0
  Routing paths:
    FE80::C803:21FF:FE78:1D, FastEthernet0/0
      Last updated 00:02:11 ago
RIPng Route Filter

RIPng uses IPv6 prefix-lists to filter routing updates. You apply prefix-lists either inbound or outbound under the RIPng process configuration mode. You may choose to associate an interface with the distribute-list, or apply it to all interfaces simultaneously by not specifying an interface.

Let’s say we want R2 to filter R4’s Loopback0 IPv6 prefix from entering the local routing table.

R2 routing table before applying route filter

R2#show ipv6 route rip
<snip>
R   ::/0 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001::1/128 [120/4]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001::3/128 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001::4/128 [120/3]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001:1:2::/48 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0

Configuration

!! Configured ipv6 prefix-list to deny 2001::4/128(R4's Loopback IP) and permit everything else. This prefix list is applied under RIPng process ID in inbound direction !!

R2#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R2(config)#ipv6 prefix-list FILTER deny  2001::4/128
R2(config)#ipv6 prefix-list FILTER permit ::/0 le 128
R2(config)#ipv6 router rip RIPV6
R2(config-rtr)# distribute-list prefix-list FILTER in
R2(config-rtr)#end

R2#show ipv6 route rip
<snip>
R   ::/0 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001::1/128 [120/4]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001::3/128 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0
R   2001:1:2::/48 [120/2]
     via FE80::C803:21FF:FE78:1D, FastEthernet0/0

After applying the route filter, routing entry for R4's Loopback IP is gone but all other routes are still present int the routing table.

R2#ping 2001::1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001::1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 52/65/84 ms

 

 

IPv6 Address Types

IPv6

::/128 – Unspecified Address

This address may only be used as a source address by an initializing host before it has  learned its own address.

IPv4 Equivalent – 0.0.0.0

::1/128 – Loopback Address

This address is used when a host talks to itself over IPv6. This often happens when one program sends data to another.

IPv4 Equivalent – 127.0.0.1

::ffff/96 – IPv4-Mapped Address

Example                  ::ffff:123.4.5.67

These addresses are used to embed IPv4 addresses in an IPv6 address. One use for this is in a dual stack transition scenario where IPv4 addresses can be mapped into an IPv6 address. See RFC 4038 for more details – https://www.ietf.org/rfc/rfc4038.txt

fc00::/7 – Unique Local Addresses (ULAs)

Example:                              fc00:1234:5678::99

These addresses are reserved for local use in home and enterprise environments and are not public address space. These addresses might not be unique, and there is no formal address registration. Packets with these addresses in the source or destination fields are not intended to be routed on the public Internet but are intended to be routed within the enterprise or organization.
See RFC 4193 for more details – https://www.ietf.org/rfc/rfc4193.txt

IPv4 Equivalent – Private or RFC1918 Addresses: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16

fe80::/10 – Link-Local Addresses

Example:   fe80::1234:5678:9abc:1234

These addresses are used on a single link or a non-routed common access network, such as an Ethernet LAN. They do not need to be unique outside of that link.
Link-local addresses may appear as the source or destination of an IPv6 packet. Routers must not forward IPv6 packets if the source or destination contains a link local address.
See RFC 4193 for more details – https://www.ietf.org/rfc/rfc4193.txt

IPv4 Equivalent – 169.254.0.0/16

2001:0000::/32 – Teredo

Example:   2001:0000:4136:e378:8000:63bf:3fff:fdd2

This is a mapped address allowing IPv6 tunneling through IPv4 NATs. The address is formed using the Teredo prefix, the server’s unique IPv4 address, flags describing the type of NAT, the obfuscated client port and the client IPv4 address, which is probably a private address. It is possible to reverse the process and identify the IPv4 address of the relay server, which can then be looked up in the relevant RIR’s Whois database.

You can do this on the following webpage:
http://www.potaroo.net/cgi-bin/ipv6addr

2001:0002::/48 – Benchmarking

Example:   2001:2::1234

These addresses are reserved for use in documentation. They should not be used as source or destination addresses.

IPv4 Equivalent – 198.18.0.0/15

2001:0010::/28 – Orchid

Example:   2001:10::1234

These addresses are used for a fixed-term experiment. They should only be visible on an end-to-end basis and routers should not see packets using them as source or destination addresses.

2002::/16 – 6to4

Example:   2002::1234

A 6to4 gateway adds its IPv4 address to this 2002::/16, creating a unique /48 prefix. As the IPv4 address of the gateway router is used to compose the IPv6 prefix, it is possible to reverse the process and identify the IPv4 address, which can then be looked up in the relevant RIR’s Whois database.

You can do this on the following webpage:
http://www.potaroo.net/cgi-bin/ipv6addr

IPv4 Equivalent – There is no equivalent but 192.88.99.0/24 has been reserved as the 6to4 relay anycast address prefix by the IETF.

2001:db8::/32 – Documentation

Example:   2001:db8::1234

These addresses are used in examples and documentation. They should never be source or destination addresses.

IPv4 Equivalent – 192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24

2000::/3 – Global Unicast

Example:   2000::1234

Other than the exceptions documented in this table, the operators of networks using these addresses can be found using the Whois servers of the RIRs listed in the registry at:
http://www.iana.org/assignments/ipv6-unicast-address-assignments

IPv4 Equivalent – No equivalent single block

ff00::/8 – Multicast

Example:   ff00::1234

These addresses are used to identify multicast groups. They should only be used as destination addresses, never as source addresses.

IPv4 Equivalent – 224.0.0.0/4