01-19-2006 06:06 AM - edited 03-03-2019 01:30 AM
Hello, I have 2 routers 1800 series with switch modules incorporated connected with IPv6. Everything is working fine except for the problem that when I assign an IPv6 address to a Vlan (using the EUI-64 format to the switch ports), it assigns the SAME interface id (last 64 bits of the IPv6) of a fastEthernet port (FE 0/0), to the vlan, causing an error problem of duplicity:
" c..T, overlaps with another prefix "
Why does the EUI-64 assigns the MAC address of the FastEthernet ports instead of the ones in the switch modules?
01-19-2006 04:41 PM
Hi,
Would you be able to post the relevant bits of your config ?
Thanks,
Paresh.
01-20-2006 08:46 AM
Thanks for the reply, but I just solved the problem. The problem was with the command IPV6 ADDRESS AUTOCONFIGURATION. This command definitely brings up a lot of trouble with VLAN ipv6 address assignation.
After some testing I concluded that:
1- If one interface has the IPV6 ADDRESS AUTOCONFIGURATION mode on, the interface could end up with more than one ipv6 global interface address.
2- You cannot assign this mode to a vlan interface without getting into configuration problems.
3- If a FastEthernet Interface has this mode on(IPV& A. A.), the router does not let you assign a global unicast address to the vlan interface, and gives the following error message:
%IPV6-6-ADDRESS: 3FFE:C00:C18:F100:213:C4FF:FE44:4961/64 can not be configurex
4- For the VLAN`s Interface ID you have to manually assign the link local address with the command line
IPV6 ADDRESS FE80::1 (or any other unique link local address) LINK-LOCAL.
This is for Vlans that are in a switch module of the same router.
All this testing was for a Cisco router 1800 series with a switch module integrated in the router.
Could be that this command is used for other specific occasions which I am not aware of.
Regards,
Grupo GTD
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide