Subject: Type 7 LSA question

From: Mike Cleary <[email-masked]>
Date: Tue, 14 Dec 2004 17:54:00 -0500

Hello,
I sent this issue before but have had no responce.  I am having a bit of
trouble trying to configure a router to send a type 7 lsa with the
forwarding address set to 0.0.0.0.  I was wondering if anyone could help
me with the configuration of this on a cisco(cisco-like) router.

The following quote is taken from section 3.2 of RFC 3101 and it leads
me to believe that this can be done.

     (1) If the Type-7 LSA has the P-bit clear, or its forwarding
         address is set to 0.0.0.0, or the most specific Type-7 address
         range that subsumes the LSA's network has DoNotAdvertise
         status, then do nothing with this Type-7 LSA and consider the
         next one in the list.  Otherwise term the LSA as translatable
         and proceed with step (2).

The current configuration steps I take are to enable the router on
network 10.10.11.0/24 in area 1 (nssa), give the router a static route
3.3.3.0/24 0.0.0.0, redistribute static on the router.  When I issue the
static route command it sometimes will allow the command sometimes it
rejects it, either way I cannot get the router to redistribute the
static route with the forwarding address set to 0.0.0.0.  Any Suggestions?
Thanks,
~Mike

--
*********************************************
Michael Cleary     Email: [email-masked]
IPv4 Consortium      UNH InterOperability Lab
121 Technology Dr., Suite 2, Durham, NH 03824
Phone: 603-862-3941    http://www.iol.unh.edu
*********************************************

---

From: Acee Lindem <[email-masked]>
Date: Tue, 14 Dec 2004 22:28:50 -0500

Mike,
Try redistributing a static route on a router internal to an NSSA that
has nothing but unnumbered interfaces in the NSSA.

Good Luck,
Acee

---

From: Mike Cleary <[email-masked]>
Date: Wed, 15 Dec 2004 16:06:43 -0500

Hello Acee,
I am a little confused.  How would I configure a router to have an
unnumbered interface in an nssa?
Thanks,
~Mike

---

From: Acee Lindem <[email-masked]>
Date: Thu, 16 Dec 2004 18:41:36 -0500

> unnumbered interface in an nssa?

Hello Mike,

It's not that easy - you must include the network for the interface 
referenced by
the unnumbered interface points and shut the referenced interface to make
it unavailable for use as a forwarding address. I'll send you a config
offline as this is somewhat vendor specific.

Good Luck,
Acee

---

From: Acee Lindem <[email-masked]>
Date: Thu, 16 Dec 2004 19:05:37 -0500

> offline as this is somewhat vendor specific.

Mike,
I take that back - there is no way to get the NSSA forwarding address to be
advertised as 0 as long as there are any up interfaces in the NSSA 
(which would
be required for your test suites).
Thanks,
Acee

---

From: Don Goodspeed <[email-masked]>
Date: Thu, 16 Dec 2004 16:33:39 -0800

Mike,

This part of the NSSA RFC was written with older implementations
in mind that did this on origination of NSSA LSAs. To support
that, when the spec was updated, the language was made stronger
on what should be transmitted but kept less strict was what should
be accepted on receipt.

So while you probably will not find an implementation that sends
0.0.0.0 as the forwarding address on origination, you should be
able to test the reception of this by using your own IOL test
tool for OSPF, or a puchased conformance or traffic generation
vendor such as Ixia (IxOS or ANVL), Agilent's RouterTester (NSX),
or Spirent's Adtech solution.

Cheers,
Don

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]]On Behalf Of Acee Lindem
Sent: Thursday, December 16, 2004 4:06 PM
To: Mailing List
Subject: Re: Type 7 LSA question

Mike,

---

From: Acee Lindem <[email-masked]>
Date: Thu, 16 Dec 2004 19:34:20 -0500

In reviewing RFC 3101, the recommended configuration is to provide
control over the P LSA option bit when redistributing (aka importing)
external  routes into an NSSA. There is no requirement on an implementation
to provide a way to set the forwarding address to 0 - although a non-zero
forwarding address is only required when the P bit is set.