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From: Stephen Hemminger <shemminger@vyatta.com>
To: Jan Engelhardt <jengelh@medozas.de>
Cc: Ed W <lists@wildgooses.com>, Simon Chen <simonchennj@gmail.com>,
	netfilter@vger.kernel.org
Subject: Re: increase the number of routing tables
Date: Mon, 30 Jan 2012 08:14:58 -0800	[thread overview]
Message-ID: <20120130081458.697d6099@nehalam.linuxnetplumber.net> (raw)
In-Reply-To: <alpine.LNX.2.01.1201300300270.21178@frira.zrqbmnf.qr>

On Mon, 30 Jan 2012 03:02:35 +0100 (CET)
Jan Engelhardt <jengelh@medozas.de> wrote:

> On Monday 2012-01-30 01:31, Stephen Hemminger wrote:
> 
> >On Sun, 29 Jan 2012 23:24:27 +0000
> >Ed W <lists@wildgooses.com> wrote:
> >
> >> On 29/01/2012 11:50, Jan Engelhardt wrote:
> >> > On Sunday 2012-01-29 03:23, Simon Chen wrote:
> >> >
> >> >> Hey folks,
> >> >>
> >> >> To my limited knowledge, Linux currently supports 256 (255?) routing
> >> >> tables defined in /etc/iproute2/rt_tables.
> >> > There are 2147483647.
> >> >
> >> 
> >> Any reason why it's not an unsigned 32bit int? (surely there is a corner 
> >> case where this is useful...)
> >> 
> >> Ed W
> >
> >The 8 bit value is enshrined in the API for 'struct rtmsg' and therefore
> >increasing it would break existing applications. 
> 
> Actually, what Ed (and me too) was wondering about was:
> 
> why does `ip route show table $[0x80000000]` not print an empty table, 
> i.e. where is it that some code uses int/s32 during parsing of 
> the argument and/or the RTA_TABLE attribute?

There are lots of places internally in ip utilities that use u32
for route table. But the route input/output message format is still limited
to 8 bits.

  reply	other threads:[~2012-01-30 16:14 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CANj2EbfR0cBaBd+t1yCZyErRpVzSC00DZohvtyazK8_9bv2aEQ@mail.gmail.com>
2012-01-29  2:23 ` increase the number of routing tables Simon Chen
2012-01-29 11:50   ` Jan Engelhardt
2012-01-29 23:24     ` Ed W
2012-01-30  0:31       ` Stephen Hemminger
2012-01-30  2:02         ` Jan Engelhardt
2012-01-30 16:14           ` Stephen Hemminger [this message]
2012-01-30 18:57             ` Jan Engelhardt
2012-01-30 19:21               ` Stephen Hemminger

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