Re: vxlan with IPv6 underlay ?

On 4 Dec 2023, at 11:25, Benoit Chesneau wrote:
> Hi,
>
> Is IPv6 underlay fully supported with FreebBSD ? I have created the a tunnel and associated an Ipv6 address to each side. I'm able to ping between each devicesl. But when I want to curl from the remote side it timeout. Locally on the remote side it is OK. Is this expected ? Should I rather create a bridge with vxlan as a member and bind nginx to it ?
>
> ```
> $ ifconfig vxlan0 create vxlanid 108 vxlanlocal AAAA:BBBB:110b:102::100 vxlanremote AAAA:BBBB:110b:102::12
> $ ifconfig vxlan0
> vxlan0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1430
> options=80020<JUMBO_MTU,LINKSTATE>
> ether 58:9c:fc:10:ff:eb
> groups: vxlan
> vxlan vni 108 local [AAAA:BBBB:102::100]:4789 remote [AAAA:BBBB:110b:102::12]:4789
> media: Ethernet autoselect (autoselect <full-duplex>)
> status: active nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
> $ ifconfig vxlan0 inet6 AAAA:BBBB:110b:300::1/64
> ````
>
> Ping from remote is ok:
> ```
> ifconfig vxlan0
> vxlan0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1430
> options=680323<RXCSUM,TXCSUM,JUMBO_MTU,TSO4,TSO6,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
> ether 58:9c:fc:10:df:1f
> inet6 fe80::5a9c:fcff:fe10:df1f%vxlan0 prefixlen 64 scopeid 0xf
> inet6 AAAA:BBBB:110b:300::2 prefixlen 64
> groups: vxlan
> vxlan vni 108 local [AAAA:BBBB110b:102::12]:4789 remote [AAAA:BBBB:110b:102::100]:4789
> media: Ethernet autoselect (autoselect <full-duplex>)
> status: active nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
> $ ping6 AAAA:BBBB:110b:300::1
> PING6(56=40+8+8 bytes) AAAA:BBBB:110b:300::2 --> AAAA:BBBB::110b:300::1
> 16 bytes from 2a0e:e701:110b:300::1, icmp_seq=0 hlim=64 time=0.071 ms
> 16 bytes from 2a0e:e701:110b:300::1, icmp_seq=1 hlim=64 time=0.078 ms
> 16 bytes from 2a0e:e701:110b:300::1, icmp_seq=2 hlim=64 time=0.076 ms
> 16 bytes from 2a0e:e701:110b:300::1, icmp_seq=3 hlim=64 time=0.104 ms
> 16 bytes from 2a0e:e701:110b:300::1, icmp_seq=4 hlim=64 time=0.077 ms^C
> ```
>
> But when I run `curl -6 -v 'http://[AAAA:BBBB:110b:300::1]'` it timeout.
>
That smells like an MTU issue. Make sure you’re not blocking ICMPv6, and check with larger ping messages.

Best regards,
Kristof