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Routing question

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mattbarkerlfc

Technical User
Jul 5, 2014
14
GB
Hi,

I have a routing question and hope someone can help me.

I need to implement routes to a new network, for the purpose of this post 10.1.45.33/29.

I already have existing routes to a 10.1.0.0 network on a /16 mask.

My question is can I add the route the 10.1.45.33/29 via the intended destination without affecting traffic to the 10.1.0.0/16 network ?

We don't use the 10.1.45.33/29 network so it isn't going to conflict with anything.

Thanks in advance,

Matt.
 
We had a similar setup once and, from what I remember, it worked fine. If there are any conflicts in the subnets the router will warn you and not take the programming.

From what I remember we needed a specific IP in a subnet to route via a VPN tunnel so we actually had a route of 10.1.0.30 255.255.255.255 via the VPN hop and it worked fine. ~ Mike
 
Hi Mike,

Thanks for the quick response.

It is actually going to be configured statically on a HP 'A' series L3 switch and redistributed into OSPF to the WAN but I guess the principal is the same.

Thanks,

Matt.

 
a router will always go for the closest match as far as routing is concerned.. if you are setting up dynamic routing through OSPF then everything should be kosher.. packets destined for your /29 network will match that route, anything else will match existing /16 route..



We must go always forward, not backward
always up, not down and always twirling twirling towards infinity.
 

Thanks for the reply.

Can the 2 subnets below be routed via different gateways ? The top one is a new, external network accessed via a firewall and the bottom one is an existing internal subnet.

10.1.1.0 255.255.255.248
10.1.0.0 255.255.0.0

Thanks,

Matt.
 
yes as i mentioned the closest bit match is always the path that is taken..

so if you have two routes - say static - :
ip route 10.1.1.0 255.255.255.248 192.168.1.1
ip route 10.1.0.0 255.255.0.0 192.192.192.1

then a packet destined for 10.1.1.2 will be routed to 192.168.1.1
a packet destined to 10.1.1.9 will be routed to 192.192.192.1

does that make sense?


We must go always forward, not backward
always up, not down and always twirling twirling towards infinity.
 

I think so !

I'll try and it and see what happens, what's the worst that can happen :)

Thanks,

Matt.

 
I've found another subnet that I might have an issue with:

10.62.0.0 255.255.254.0 is a new subnet
10.62.0.0 255.255.0.0 is an existing subnet

The gateway address at the existing subnet is 10.62.0.254, won't that conflict with the new subnet ?

Matt.
 
that might cause an issue..
10.62.0.254 is part of both 10.62.0.0/23 and 10.62.0.0/16

really depends on the configuration .. i mean end of the day routers will route.. but post config .. cause this one is a bit more iffy ..


We must go always forward, not backward
always up, not down and always twirling twirling towards infinity.
 
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