vyos@vyos# set interfaces dummy dum0 address 192.0.2.8/31 Invalid value Value validation failed Set failed
vyos@vyos# set interfaces dummy dum0 address 192.0.2.9/31
This happened to be an issue before (fixed in T1425, and reintroduced by fixing T2548)
The root cause is that ipaddrcheck is not properly aware of the /31 mask
$ ipaddrcheck --is-ipv4-host 192.0.2.9/31 $ echo $? 0 $ ipaddrcheck --is-ipv4-host 192.0.2.8/31 $ echo $? 1
Why /31? https://tools.ietf.org/html/rfc3021
Proposed validator for host https://github.com/vyos/vyos-1x/blob/current/src/validators/ipv4-host
#!/bin/sh if [ `echo $1 | grep "/31" | wc -l` -eq "1" ]; then ipaddrcheck --is-any-cidr $1 else ipaddrcheck --is-ipv4-host $1 fi
i'm wondering if this is the right approach.
This works as a workaround, but this needs to be added to the ipaddrcheck validator as an allowed host-address and not be done in a shell script
Clearly a workaround is the fastest way to "fix" VyOS, but the backend code should be fixed, too. This is either ipaddrcheck https://github.com/vyos/ipaddrcheck or libcidr.
The mentioned PR can't be accepted (see GitHub discussion) as it will break IPv6.
I'm pretty sure it's my failure to correctly handle an edge case. I'll look into it today, should be simple enough.