Hi All, If I have a vlan-Id on an interface with an ipv6 address, then I am unable to ping a real router. The problem is that the Neighbour Solicitation originated from the Centos machine is missing the Vlan-Id in the packet. Therefore a real router will drop such a packet. I have tried this with Centos 4.7 and with Centos 5.5 with the same result.
If I originate the first Neighbour Solicitation from the Router (which contains the Vlan-Id), then Linux learns the Mac address correctly and bidirectional ping works. This is a workaround that I am using at the moment, but I would like to avoid doing this all the time (especially when there is a timeout of the neighbour information).
This problem does not exist for Ipv4 (i.e. ARP packets originated from Centos contain the Vlan-Id as expected).
Here is my topology. Router--port1/1/1.1-------------------eth2---(eth2.1)--Centos 10.10.8.1/24 1.1.1.2 10.10.8.10 (3ffe::a0a:801/120) (3ffe::a0a:80a/120) port 1/1/1.21--------------------------eth2.21 (3ffe::a0f:801/120) (3ffe::a0f:80a/120)
(KANRTB1):~ > cat /etc/*-release CentOS release 5.5 (Final) (KANRTB1):~ > cat /proc/version Linux version 2.6.18-194.el5 (mockbuild@builder16.centos.org) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-48)) #1 SMP Fri Apr 2 14:58:35 EDT 2010
(KANRTB1):~ > ip -6 addr show <SNIP> 687: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 500 inet6 3ffe::a0f:80a/128 scope global valid_lft forever preferred_lft forever inet6 3ffe::a0a:80a/120 scope global valid_lft forever preferred_lft forever inet6 fe80::2ff:7ff:fe00:2/64 scope link valid_lft forever preferred_lft forever <SNIP> 692: eth2.1@eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 inet6 3ffe::a0a:80a/120 scope global valid_lft forever preferred_lft forever inet6 fe80::2ff:7ff:fe00:2/64 scope link valid_lft forever preferred_lft forever 693: eth2.21@eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 inet6 3ffe::a0f:80a/120 scope global valid_lft forever preferred_lft forever inet6 fe80::2ff:7ff:fe00:2/64 scope link valid_lft forever preferred_lft forever <SNIP>
KANRTB1):~ > ifconfig <SNIP>
eth2 Link encap:Ethernet HWaddr 00:FF:07:00:00:02 inet addr:1.1.1.2 Bcast:1.1.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:29 errors:0 dropped:0 overruns:0 frame:0 TX packets:313 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:500 RX bytes:3330 (3.2 KiB) TX bytes:48442 (47.3 KiB)
eth2.1 Link encap:Ethernet HWaddr 00:FF:07:00:00:02 inet addr:10.10.8.10 Bcast:10.10.8.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:29 errors:0 dropped:0 overruns:0 frame:0 TX packets:64 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:2924 (2.8 KiB) TX bytes:10071 (9.8 KiB)
eth2.21 Link encap:Ethernet HWaddr 00:FF:07:00:00:02 inet addr:10.15.8.10 Bcast:10.15.8.10 Mask:255.255.255.255 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:34 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 b) TX bytes:6313 (6.1 KiB)
<SNIP>
Any help/easy fixes/pointers are much appreciated. thanks, Rohit