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Basic IPv6 Connectivity

I have two routers, a 7206 and an 2600 connected via a point-to-point T1. IPv4 connectivity works. Now I'm tring to bring up IPv6 connectivity. Only neither router seems to 'see' the other. While a route to the subnet which is the T1 connection appears I can't even ping either side. Of course I [and everyone :)] am new to IPv6 so I'm potentially overlooking something.

Also, is the "ipv6 enable" required for an interface with an IPv6 address assgined? It seems like "ipv6 enable" would be implicit if an IPv6 address is assigned. I've found documentation that specifies "ipv6 enable" and documentation that doesn't. And would "ipv6 enable" be required on an unnumbered interface that is tied to an interface where IPv6 is enabled?

Cisco 7206

---------------------------------- Abbreviated config: ipv6 unicast-routing ! interface Loopback0 ip address 10.6.42.1 255.255.255.255 ipv6 address FDB5:60DA:9B8A:2::/64 eui-64 ipv6 enable ipv6 rip mi enable ! interface FastEthernet0/0 ip address 192.168.1.6 255.255.255.0 duplex full speed auto ipv6 address FDB5:60DA:9B8A:1::6/64 ipv6 rip mi enable ! interface Serial2/0/1:0 description GRD-RDG PtP bandwidth 1544 ip unnumbered Loopback0 ipv6 unnumbered Loopback0 service-policy output voip ipv6 enable ! ipv6 router rip mi !

seaweed>show ipv6 route IPv6 Routing Table - 6 entries Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP U - Per-user Static route I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2 ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2 C FDB5:60DA:9B8A:1::/64 [0/0] via ::, FastEthernet0/0 L FDB5:60DA:9B8A:1::6/128 [0/0] via ::, FastEthernet0/0 C FDB5:60DA:9B8A:2::/64 [0/0] via ::, Loopback0 L FDB5:60DA:9B8A:2:21A:2FFF:FE89:9608/128 [0/0] via ::, Loopback0 L FE80::/10 [0/0] via ::, Null0 L FF00::/8 [0/0] via ::, Null0 seaweed>show ipv6 ne seaweed>

Cisco 2600

------------------------------------ Abbreviated config: ipv6 unicast-routing ! interface Loopback0 ip address 10.6.42.33 255.255.255.255 ipv6 address FDB5:60DA:9B8A:2::/64 eui-64 ipv6 enable ipv6 rip mi enable ! interface Ethernet0/0 ip address 192.168.33.19 255.255.255.0 ip helper-address 192.168.1.9 no ip route-cache no ip mroute-cache half-duplex ipv6 address FDB5:60DA:9B8A:21::13/64 ipv6 rip mi enable no keepalive ! interface Serial0/0 description RDG-GRD PtP bandwidth 1544 ip unnumbered Loopback0 service-policy output voip no ip mroute-cache ipv6 unnumbered Loopback0 ipv6 enable ! ipv6 router rip mi !

rdggate#show ipv6 ne rdggate#show ipv6 route IPv6 Routing Table - 6 entries Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP U - Per-user Static route I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2 ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2 C FDB5:60DA:9B8A:2::/64 [0/0] via ::, Loopback0 L FDB5:60DA:9B8A:2:205:9BFF:FEAF:2080/128 [0/0] via ::, Loopback0 C FDB5:60DA:9B8A:21::/64 [0/0] via ::, Ethernet0/0 L FDB5:60DA:9B8A:21::13/128 [0/0] via ::, Ethernet0/0 L FE80::/10 [0/0] via ::, Null0 L FF00::/8 [0/0] via ::, Null0 rdggate#ping FDB5:60DA:9B8A:2:21A:2FFF:FE89:9608

Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to FDB5:60DA:9B8A:2:21A:2FFF:FE89:9608, timeout is 2 seconds: ..... Success rate is 0 percent (0/5)

Reply to
whitemice
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I would try configing IPv6 global address directly on the Serial interface instead of using unnumbered

7206 ===

int s 2/0/1:0 ipv6 address 1::1/64

2600 ===

int s 0/0 ipv6 address 1::2/64

sh ipv6 int

sh ipv6 nei

Reply to
Merv

Why is it new to everyone? I've run beta IPv6 code on cisco a 3102 and

2500's and 3600's in the late 90's? (I'm guessing I'm close to the only one to have run up those beta image on a 3102 though :)

The ipv6 enabled is required on each interface talking. Its a relatively recent invention, since IPv6 is autoconfiguring, you don't necessarily have to put an IPv6 address on an interface. The intention of having "ipv6 enabled" being requires is so that you don't turn on the global IPv6 knob and suddenly have 100's of ports auto-configure and talk IPv6 to the global Net on IPv6 potentially ignoring a firewall there.. You only enable the interface when you're ready to talk.

Also, since IPv6 has link-local IP addressing, why are you trying to do unnumbered with it? It already has link-local IPv6 addressing as it is. If you don't want to use global IPs, use the local link-local IPs?

I'd lose the un-numbered interfaces out of your config, let the interfaces have their link-local IPs. Ping across the link with the link-local ones.

Also note that your IPv6 rip isn't working, and you have no static routing in place. Thats probably why your pings don't return. I'd rip it out to be simpler. No un-numbered interfacing. No RIP, just an IP per interface, and static routing.

Reply to
Doug McIntyre

The "ipv6 enable" command is used to bring up an interface with a link- local address only. If an interface has a global IPv6 address configured then "ipv6 enable" is not required. Also removing ipv6 enable from an interface that has an IPv6 global address configured will not disable IPv6 processing on that interface.

For router-to-router links we should not require IPv6 ND router advertisements so disable as should be using an IGP. Also do not require IPv6 DUD on router-to-router links so put max time as IGP will be used to discover if neighbour has vanished. Use IGP fast convergence timers or BFD if required

ipv6 nd ra suppress ipv6 nd ns-interval 15000 ipv6 nd reachable-time 3600000

Also can use ra suppression on LAN interfaces when a first-hop reachability protocol such as HSRP or VRRP is used.

Reply to
Merv

Thanks everybody for the feedback & details; it was indeed the unnumbered interfaces that was messing it up. Needed to be my head out of IPv4 mode! Routing protocol and all seems to be working now.

Router#1: ipv6 unicast-routing ! interface FastEthernet0/0 ip address 192.168.1.6 255.255.255.0 ipv6 address FDB5:60DA:9B8A:1::6/64 ipv6 rip mi enable ! interface Serial2/0/1:0 ipv6 enable ipv6 rip mi enable ! ipv6 route 2001::/16 FDB5:60DA:9B8A:1::37 100 ipv6 route 2002::/16 FDB5:60DA:9B8A:1::37 100 ipv6 router rip mi redistribute static !

Router#2: ipv6 unicast-routing ! interface FastEthernet0/0 ipv6 address FDB5:60DA:9B8A:21::13/64 ipv6 rip mi enable ! interface Serial2/0/1:0 ipv6 enable ipv6 rip mi enable ! ipv6 router rip mi !

Reply to
whitemice

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