This article explains possible reason for a IPv6 route is not reachable when you try to ping without the source knob.
You Will notice that the IPv6 IP is not reachable from the gateway without mentioning the source knob.
user@host> ping 2a04:4043:0:3::10
PING6(56=40+8+8 bytes) 2a04:4043:0:3::3 --> 2a04:4043:0:3::10
64 bytes from 2a04:4043:0:3::3: Destination Host Unreachable
Vr TC Flow Plen Nxt Hlim
6 00 00000 0010 3a 40
2a04:4043:0:3::3->2a04:4043:0:3::10
ICMP6: type = 128, code = 0
^C
--- 2a04:4043:0:3::10 ping6 statistics ---
8 packets transmitted, 0 packets received, 100% packet loss
However the same IP would be reachable when you ping with the source knob.
user@host> ping 2a04:4043:0:3::10 source 2a04:4043:0:3::1
PING6(56=40+8+8 bytes) 2a04:4043:0:3::1 --> 2a04:4043:0:3::10
16 bytes from 2a04:4043:0:3::10, icmp_seq=0 hlim=64 time=1.195 ms
16 bytes from 2a04:4043:0:3::10, icmp_seq=1 hlim=64 time=0.536 ms
16 bytes from 2a04:4043:0:3::10, icmp_seq=2 hlim=64 time=0.586 ms
16 bytes from 2a04:4043:0:3::10, icmp_seq=3 hlim=64 time=0.527 ms
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max/std-dev = 0.527/0.711/1.195/0.280 ms
This is caused due to the combination of virtual-gateway and mac
Combination 1
user@host# show interfaces irb.6022
proxy-macip-advertisement;
virtual-gateway-accept-data;
family inet {
address <IPv4 Address>;
}
family inet6 {
address <IPv6 Address> {
virtual-gateway-address <virtual ipv6 IP>;
mac <mac-address>;
virtual-gateway-v6-mac <virtual mac address>;
Combination 2
address <ipv4 address {
virtual-gateway-address <virtual gateway ip>;
address <ipv6 address> {
virtual-gateway-address virtual ipv6 address;
mac <MAC address >;
virtual-gateway-v4-mac <virtual gateway mac for ipv4>;
virtual-gateway-v6-mac <virtual gateway Mac for ipv6>;
In both combinations we could see that the ping using the configured ipv6 address.
Monitor traffic interface output
4:20:43.292832 In IP6 2a04:4043:0:3::3 > ff02::1:ff00:10: ICMP6, neighbor solicitation, who has 2a04:4043:0:3::10, length 32
14:20:43.292910 Out IP6 2a04:4043:0:3::10 > 2a04:4043:0:3::3: ICMP6, neighbor advertisement, tgt is 2a04:4043:0:3::10, length 32
user@host> show ipv6 neighbors
IPv6 Address Linklayer Address State Exp Rtr Secure Interface
2a04:4043:0:3::1 00:00:5e:05:02:01 stale 938 no no ae2.0
2a04:4043:0:3::2 f0:1c:2d:be:85:1c stale 1063 yes no ae2.0
2a04:4043:0:3::3 f0:1c:2d:be:85:1c stale 1058 yes no ae2.0
When we change the config as below.
Working config:
address <ipv4 address>;
address <ipv6 address>;
mac <MAC address ?;
working config 2
address 5.10.19.18/29 {
virtual-gateway-address 5.10.19.17;
virtual-gateway-address <virtual ipv6 address>;
virtual-gateway-v4-mac <virtual ipv4 gateway MAC address>;
virtual-gateway-v6-mac <virtual ipv6 gateway MAC address>;
After changing the config we could see that the neighbour discovery message switches to link local address.
14:29:52.130395 In IP6 fe80::f24b:3a17:86ec:9868 > ff02::1:ff00:10: ICMP6, neighbor solicitation, who has 2a04:4043:0:3::10, length 32
14:29:52.130466 Out IP6 fe80::7e25:86ff:fed5:fd16 > fe80::f24b:3a17:86ec:9868: ICMP6, neighbor advertisement, tgt is 2a04:4043:0:3::10, length 32