network x.x.x.x n.n.n.n

surfthegecko

Hi,

Whats the difference between the following routing network statements, dont they both achieve the same goal:

1. network 172.16.1.1 0.0.0.0
This puts network 172.16.1.0 / 24 into the routing table

2. network 172.16.1.0 0.0.0.255
This puts network 172.16.1.0 / 24 into the routing table


Im sure im missing something here?

Thanks for your help in advance

georgemc

1. network 172.16.1.1 0.0.0.0
This puts network 172.16.1.0 / 24 into the routing table - NOT TRUE

your statement provides an exact match for host 172.16.1.1


2. network 172.16.1.0 0.0.0.255
This puts network 172.16.1.0 / 24 into the routing table - TRUE

surfthegecko wrote: »

Hi,

Whats the difference between the following routing network statements, dont they both achieve the same goal:

1. network 172.16.1.1 0.0.0.0
This puts network 172.16.1.0 / 24 into the routing table

2. network 172.16.1.0 0.0.0.255
This puts network 172.16.1.0 / 24 into the routing table


Im sure im missing something here?

Thanks for your help in advance

surfthegecko

Just did this on Router1

int loopback 196 - ip address 196.1.1.1 255.255.255.0
int loopback 197 - ip address 197.1.1.1 255.255.255.0

router eigrp 100
network 196.1.1.1 0.0.0.0
network 197.1.1.1 0.0.0.255

This is what was displayed in Router2's routing table
D 197.1.1.0/24 [90/20640000] via 10.1.3.1, 00:00:38, Serial1/0
D 196.1.1.0/24 [90/20640000] via 10.1.3.1, 00:00:53, Serial1/0


Am I being daft, but it just seems to have done them both as /24 instead of the 196 as an exact match?

Edit: I know the routing table is only supposed to show the networks, but then whats the point of specify exact network wildcards?

Xenz

EIGRP doesn't work the same as OSPF. Try this in OSPF and you'll get the host route you're looking for.

What GeorgeMC is saying is that when you do network 196.1.1.1 0.0.0.0 you will only use the interface 196.1.1.1 to participate in EIGRP rather than the whole 196.1.1.0/24 range.

I honestly don't know how/or if it's possible to install host routes in EIGRP. I know OSPF works the way you're imagining though.

jmc012

surfthegecko wrote: »

Hi,

Whats the difference between the following routing network statements, dont they both achieve the same goal:

1. network 172.16.1.1 0.0.0.0
This puts network 172.16.1.0 / 24 into the routing table

2. network 172.16.1.0 0.0.0.255
This puts network 172.16.1.0 / 24 into the routing table


Im sure im missing something here?

Thanks for your help in advance

Do you have auto summary turned on under the eigrp process? It sounds like you need to turn it off. Just do a #no auto-summary.

surfthegecko

I already have no auto-summary configured under my eigrp zone, I have however just noticed that although it displays them the same in the routing table, it displays them differently in the running config

router eigrp 100
network 1.0.0.0
network 10.0.0.0
network 172.16.0.0
network 196.1.1.1 0.0.0.0
network 197.1.1.0
no auto-summary

So I'm guessing what this is actually saying is:.....

If I had 3 interfaces - 196.1.1.1 /24, 196.2.2.2 /24, 196.3.3.3 /24 that the only interface within the 196 range that is going to advertise the 196 networks is out of interface 196.1.1.1

Would this make sense?

jmc012

surfthegecko wrote: »

I already have no auto-summary configured under my eigrp zone, I have however just noticed that although it displays them the same in the routing table, it displays them differently in the running config

router eigrp 100
network 1.0.0.0
network 10.0.0.0
network 172.16.0.0
network 196.1.1.1 0.0.0.0
network 197.1.1.0
no auto-summary

So I'm guessing what this is actually saying is:.....

If I had 3 interfaces - 196.1.1.1 /24, 196.2.2.2 /24, 196.3.3.3 /24 that the only interface within the 196 range that is going to advertise the 196 networks is out of interface 196.1.1.1

Would this make sense?

Yes, it will just advertise that specific route and turn eigrp on that interface. The other ones that don't have wildcard masks applied default to classful boundaries.

surfthegecko

But before it advertises the others I would have to make a 2nd routing statement to identify the other two 196 networks

Cool.

Thanks everyone