IPv6 prefix length error

[Khuu, Linh Contractor]

Thanks Mark for your recommendation!!!

However, in the ifconfig -a output, I have:

lo0: flags=e08084b<UP,BROADCAST,LOOPBACK,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64BIT>
        inet 127.0.0.1 netmask 0xff000000 broadcast 127.255.255.255
        inet6 ::1/128

But I still see the error in the log "28-Apr-2011 23:58:02.935 general: prefix length for ::1 is unknown (assume 128)"

As for the prefix length of the IPv6 address of the interface, we have 2001:1930:e03::e/48, but the log still show the error of (assume 128).

Will this error cause any problem with named to resolve IPv6 addresses?

Linh Khuu
Network Security Specialist
MicroTech ESS Contract
Office: 410-966-0798
Pager: 410-232-2350
Email: Linh.Khuu at ssa.gov


-----Original Message-----
From: Mark Andrews [mailto:marka at isc.org] 
Sent: Thursday, April 28, 2011 7:53 PM
To: Khuu, Linh Contractor
Cc: 'bind-users at lists.isc.org'
Subject: Re: IPv6 prefix length error


In message <F80B214C2304C641B917B47051D743C407F0297937 at HQ-MB-08.ba.ad.ssa.gov>,
 "Khuu, Linh Contractor" writes:
> Hello,
> 
> We just added the IPv6 address on our DNS servers. When we started named, w=
> e see these errors in the log:
> 
> prefix length for 2001:1930:e03::e is unknown (assume 128)
> prefix length for ::1 is unknown (assume 128)
> 
> So far, named is still running fine... I can't find any information to corr=
> ect these errors.
> 
> Thanks,
> Linh Khuu

These are reported because named was unable to determine the prefix
length associated with the address.  Usually because no one has
documented the OS specicif method for doing this or it is write
only.

Please contact your OS vendor so they can address the issue.

The major implication of not having this information is that the builtin
"localnets" acl will not be complete.  Instead of 2001:1930:e03::/64,
assuming it is a /64, it will have 2001:1930:e03::e/128.

Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org