[quagga-users 14081] Re: OSPFv3 daemon inconsistencies between Quagga versions (and problems!)

Mark Kamichoff prox at prolixium.com
Wed Jul 29 22:49:39 BST 2015


On Thu, May 21, 2015 at 06:12:49PM +0100, Pedro Ribeiro wrote:
> Hello,
> 
> Sorry for the long email, I'm trying to send all the information that seems
> important for the problem analysts.
> 
> I'm using a few PCs working as routers with Quagga in a mixed vendor
> scenario.
> After upgrading Quagga in one of the routers, a Cisco router became
> inaccessible over IPv6.
> After analysis I've found the route to the Cisco's loopback interface was
> missing in the upgraded Quagga.
> With some testing I've concluded that changing the address prefix from /128
> to /127 changed the behaviour
> of the newer Quagga and made the route appear in the table (with an
> undesired prefix but that's a minor problem).
> 
> Following I'm presenting a few command outputs from 3 of the equipments.
> The Cisco that become inaccessible, an old Quagga (0.99.22.4) and the newer
> (0.99.24.1).

[.snip.]

I'm seeing the exact same behavior after upgrading to 0.99.24.1 but with
a Junos-based firewall.  The Junos firewall (SRX100) is sending the
following:

Age:    6 Type: Intra-Prefix
Link State ID: 0.0.0.1
Advertising Router: 10.3.4.11
LS Sequence Number: 0x800035c8
CheckSum: 0x17e2 Length: 52
Duration: 00:00:02
     Number of Prefix: 1
     Reference: Router Id: 0.0.0.0 Adv: 10.3.4.11
     Prefix Options: --|--|LA|--
     Prefix: 2001:48c8:1:104::14/128

But, it's not being added to the RIB.

The major difference I see here between this and others that are
accepted is that Junos sets the LA bit.  Here's a prefix that's
accepted (originated from another Quagga box, actually):

Age:  473 Type: Intra-Prefix
Link State ID: 0.0.0.0
Advertising Router: 10.3.4.28
LS Sequence Number: 0x8000262d
CheckSum: 0xf75b Length: 52
Duration: 00:07:52
     Number of Prefix: 1
     Reference: Router Id: 0.0.0.0 Adv: 10.3.4.28
     Prefix Options: --|--|--|--
     Prefix: 2001:48c8:1:104::3c/128

... no LA bit, but the rest of the LSID appears similar.

The LA bit is described in RFC
5340 under A.4.1.1.1:

>>>>>>>

   LA-bit
      The "local address" capability bit.  If set, the prefix is
      actually an IPv6 interface address of the Advertising Router.
      Advertisement of local interface addresses is described in
      Section 4.4.3.9.  An implementation MAY also set the LA-bit for
      prefixes advertised with a host PrefixLength (128).

>>>>>>>

http://tools.ietf.org/html/rfc5340#appendix-A.4.1.1

Is Quagga checking the LA bit and doing something wrong with it?

I'm guessing this is a bug/regression.

- Mark

-- 
Mark Kamichoff
prox at prolixium.com
http://www.prolixium.com/
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