Subject: Route set with REJECT flag in the IP route table - regd

From: [email-masked] (G. Sudarshan)
Date: Fri, 22 May 1998 18:01:21 -0530 (IST)

Hello !

The following has details of a RIP implementation. I need clarification
for the problem mentioned. Thanks in advance.

have a nice day,
sudarshan
 
Salient features of RIP daemon implemented :
----------------
I have a RIP daemon which sends and receives RIPv1 packets. It also receives
RIPv2 packet and uses only the subnet mask of the route entries. All other
RIPv2 spcific information are ignored. The daemon does not send RIPv2 packets.

The RIPv2 routes are installed in IP route table with the subnet mask
received as part of the RIP packet. The host routes are not installed in
IP route table but interface network information is installed in IP route
table. 

Problem :
-------
Assume a router has 2 interfaces configured with 164.164.10.100, 
164.164.20.100 with all netmask being 255.255.255.0.
Assume that the same router has another interface with IP address 
165.165.10.100 and netmask 255.255.0.0 configured to reach router R.
RIP daemon should not advertise 164.164.10.0 and 164.164.20.0 to 
router R (as per RIPv1 RFC). But it will advertise route information
for 164.164.10.0 to the interface with IP address 164.164.20.100 and vice-versa.
The router has a default route to router R. This default route is selected if
no other route is available.
Doubts :
1. What route information is advertised to router R ?
2. If e.g. 164.164.0.0 is advertised then how my 
router (with RIP daemon running is the only routing protocol running)
will ensure that a packet to 164.164.30.100 cannot be forwarded ?

---

From: Acee Lindem <[email-masked]>
Date: Fri, 22 May 1998 10:29:21 -0400

> Salient features of RIP daemon implemented :

This doesn't sound too useful. Are you aware of Veron Schryver's routed 
implementation including RIPv2 and IRDP? I have a copy but can't seem to
find the ftp achive site right now. 

> 1. What route information is advertised to router R ?

You can either advertise nothing or 164.164/16. 

> will ensure that a packet to 164.164.30.100 cannot be forwarded ?

You should add a reject route to 164.164/16. 

-- 
Acee