`ip addr show' shows maximum of 56 addresses?

`ip addr show' shows maximum of 56 addresses?

[Ben Jencks]

I'm finding that ip addr show will only give me up to 56 addresses:

$ ip -6 addr show lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
$ for i in `seq 55` ; do sudo ip addr del fd9a:704e:4d65:136d::`printf '%x\n' $i`/128 dev lo ; done
$ ip addr show lo | grep inet6 | wc -l
56
$ ip addr show lo | grep ' ::1'
    inet6 ::1/128 scope host 
$ sudo ip addr add fd9a:704e:4d65:136d::`printf '%x\n' 56`/128 dev lo
$ ip addr show lo | grep inet6 | wc -l
56
$ ifconfig lo | grep inet6 | wc -l
57
$ ip addr show lo | grep ' ::1'
<no output>

It doesn't even help to specify the address explicitly:

$ ip addr show dev lo to ::1
<no output>

(Ubuntu kernel 2.6.32, tested with both distributed and latest git iproute2)

I searched for this issue, and even looked in the iproute2/ip/ipaddress.c and couldn't find any explicit limits. Is there a maximum netlink message size causing problems?

Sorry if this question is too user-ish for a dev list, but both linux-net and lartc looked dead.

Thanks,
-Ben

Re: `ip addr show' shows maximum of 56 addresses?

[Eric Dumazet]

Le lundi 05 décembre 2011 à 16:12 -0500, Ben Jencks a écrit :
> I'm finding that ip addr show will only give me up to 56 addresses:
> 
> $ ip -6 addr show lo
> 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 
>     inet6 ::1/128 scope host 
>        valid_lft forever preferred_lft forever
> $ for i in `seq 55` ; do sudo ip addr del fd9a:704e:4d65:136d::`printf '%x\n' $i`/128 dev lo ; done
> $ ip addr show lo | grep inet6 | wc -l
> 56
> $ ip addr show lo | grep ' ::1'
>     inet6 ::1/128 scope host 
> $ sudo ip addr add fd9a:704e:4d65:136d::`printf '%x\n' 56`/128 dev lo
> $ ip addr show lo | grep inet6 | wc -l
> 56
> $ ifconfig lo | grep inet6 | wc -l
> 57
> $ ip addr show lo | grep ' ::1'
> <no output>
> 
> It doesn't even help to specify the address explicitly:
> 
> $ ip addr show dev lo to ::1
> <no output>
> 
> (Ubuntu kernel 2.6.32, tested with both distributed and latest git iproute2)
> 
> I searched for this issue, and even looked in the iproute2/ip/ipaddress.c and couldn't find any explicit limits. Is there a maximum netlink message size causing problems?
> 
> Sorry if this question is too user-ish for a dev list, but both linux-net and lartc looked dead.
> 
> Thanks,
> -Ben--

This was fixed two years ago by commit bcd323262a94b14b in 2.6.33
(ipv6: Allow inet6_dump_addr() to handle more than 64 addresses)

Re: `ip addr show' shows maximum of 56 addresses?

[Eric Dumazet]

Le mardi 06 décembre 2011 à 03:48 +0000, Ben Hutchings a écrit :

> Seems like a candidate for 2.6.32.y.  I don't think it depends on any of
> your other changes for 2.6.33, does it?

Yes, this is a candidate for 2.6.32.y, I see no dependencies.

Re: `ip addr show' shows maximum of 56 addresses?

[Ben Hutchings]

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Eric Dumazet wrote:
> Le lundi 05 décembre 2011 à 16:12 -0500, Ben Jencks a écrit :
> > I'm finding that ip addr show will only give me up to 56 addresses:
> > 
> > $ ip -6 addr show lo
> > 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 
> >     inet6 ::1/128 scope host 
> >        valid_lft forever preferred_lft forever
> > $ for i in `seq 55` ; do sudo ip addr del fd9a:704e:4d65:136d::`printf '%x\n' $i`/128 dev lo ; done
> > $ ip addr show lo | grep inet6 | wc -l
> > 56
> > $ ip addr show lo | grep ' ::1'
> >     inet6 ::1/128 scope host 
> > $ sudo ip addr add fd9a:704e:4d65:136d::`printf '%x\n' 56`/128 dev lo
> > $ ip addr show lo | grep inet6 | wc -l
> > 56
> > $ ifconfig lo | grep inet6 | wc -l
> > 57
> > $ ip addr show lo | grep ' ::1'
> > <no output>
> > 
> > It doesn't even help to specify the address explicitly:
> > 
> > $ ip addr show dev lo to ::1
> > <no output>
> > 
> > (Ubuntu kernel 2.6.32, tested with both distributed and latest git iproute2)
> > 
> > I searched for this issue, and even looked in the iproute2/ip/ipaddress.c and couldn't find any explicit limits. Is there a maximum netlink message size causing problems?
> > 
> > Sorry if this question is too user-ish for a dev list, but both linux-net and lartc looked dead.
> > 
> > Thanks,
> > -Ben--
> 
> This was fixed two years ago by commit bcd323262a94b14b in 2.6.33
> (ipv6: Allow inet6_dump_addr() to handle more than 64 addresses)

Seems like a candidate for 2.6.32.y.  I don't think it depends on any of
your other changes for 2.6.33, does it?

Ben.

-- 
Ben Hutchings
Absolutum obsoletum. (If it works, it's out of date.) - Stafford Beer

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