OSPF, EIGRP...wildcards questions

Hello,

I'll try to be as clear as possible:

In Lammle's book, he only uses wildcards when configuring OSPF. In this lab packet--->https://learningnetwork.cisco.com/docs/DOC-12808, lab NA-4-4-EIGRP uses wildcards. So I'm confused...EIGRP uses wildcards when setting it up? Lammle does not mention wildcards in regards to EIGRP.

His book says:

Router(config)#router eigrp 20
Router(config-router)#network 172.16.0.0
Router(config-router)#network 10.0.0.0

as an example.

My other question is with OSPF:

In lab NA-4-3-OSPF I'm having trouble understanding where these two network statements come from:

Ranet-BR(config-router)#network 128.0.6.156 0.0.0.3 area 0
Ranet-HQ(config-router)#network 128.0.6.156 0.0.0.3 area 0

I see where these two come from (both are the subnets of the two LAN's):

Ranet-BR(config-router)#network 128.0.6.144 0.0.0.7 area 0
Ranet-HQ(config-router)#network 128.0.6.128 0.0.0.15 area 0

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Comments

sizeon

1) With EIGRP, wildcards are OPTIONAL. You do not have to use them.

2) Not really sure what you are asking but 0.0.0.3 is the same as 0.0.0.252

Roguetadhg

I suspect you mean to say: 255.255.255.252. This isn't the same as 0.0.0.3. First is a subnet mask. Not a wild-card mask. Reverse, yes. Not the same. Not used interchangeably. Mostly... I say mostly because of what I'm about to show you!

255.255.255.252 = 1111 1111.1111 1111.1111 1111.1111 1100
0.0.0.3 = 0000 0000 . 0000 0000 . 0000 0000.0000 0011

However... For EIGRP, you can input either wild-card or a subnet mask. It will show the wild-card on a show run. Just know it can take Wild-card, like OSPF. It can also not use any mask and rely on the class boundaries! Amazing!

Heres some input I pulled up to show you the latter information

Gunther(config)#router eigrp 1
Gunther(config-router)#[COLOR=#ff0000]network 10.0.0.0[/COLOR][COLOR=#0000ff] [B] 255[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#0000ff][B]255[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#0000ff][B]255[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#008000][B]0[/B][/COLOR]
Gunther(config-router)#network 12.0.0.0
Gunther(config-router)#network 14.0.0.0 0.0.0.255
Gunther(config-router)#do show run | se router
router eigrp 1
 [COLOR=#ff0000]network 10.0.0.0[/COLOR] [COLOR=#008000][B] 0[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#008000][B]0[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#008000][B]0[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#0000ff][B]255[/B][/COLOR]
 network 12.0.0.0
 network 14.0.0.0 0.0.0.255
 auto-summary
Gunther(config-router)#

Can't open the topologies - I guess I don't have packet tracer installed. I can't find the installation file on my computer $:\$

vishaw1986

Hey

If you want to run EIGRP on a specific interface , then use network command with the wild card mask .
E.g Suppose you hav ethree interface with address 1.1.1.1 , 1.1.2.1 , 1.1.3.1 with /24 mask each. You colud just use classfull network command with 1.0.0.0 and this would enable eigrp on all interface that start with 1 . And If you don't want your network to learn 1.1.2.1 address through eigrp , in that case your use wildcard mask . Network 1.1.1.0 0.0.0.255 and 1.1.3.0 0.0.0.255 . In this manner EIGRP get enable on all interface except 1.1.2.1 . Hope this helps you

For Your Next question , m not able to open the topology in my system , so sorry .

sizeon

Roguetadhg wrote: »
I suspect you mean to say: 255.255.255.252. This isn't the same as 0.0.0.3. First is a subnet mask. Not a wild-card mask. Reverse, yes. Not the same. Not used interchangeably. Mostly... I say mostly because of what I'm about to show you!

255.255.255.252 = 1111 1111.1111 1111.1111 1111.1111 1100
0.0.0.3 = 0000 0000 . 0000 0000 . 0000 0000.0000 0011

However... For EIGRP, you can input either wild-card or a subnet mask. It will show the wild-card on a show run. Just know it can take Wild-card, like OSPF. It can also not use any mask and rely on the class boundaries! Amazing!

Heres some input I pulled up to show you the latter information
Gunther(config)#router eigrp 1
Gunther(config-router)#[COLOR=#ff0000]network 10.0.0.0[/COLOR][COLOR=#0000ff] [B] 255[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#0000ff][B]255[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#0000ff][B]255[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#008000][B]0[/B][/COLOR]
Gunther(config-router)#network 12.0.0.0
Gunther(config-router)#network 14.0.0.0 0.0.0.255
Gunther(config-router)#do show run | se router
router eigrp 1
 [COLOR=#ff0000]network 10.0.0.0[/COLOR] [COLOR=#008000][B] 0[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#008000][B]0[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#008000][B]0[/B][/COLOR][COLOR=#ff0000][B].[/B][/COLOR][COLOR=#0000ff][B]255[/B][/COLOR]
 network 12.0.0.0
 network 14.0.0.0 0.0.0.255
 auto-summary
Gunther(config-router)#
Can't open the topologies - I guess I don't have packet tracer installed. I can't find the installation file on my computer

0.0.0.252 is the same thing as 0.0.0.3.

binaryhat

Definitely helps...wildcards are optional for EIGRP...except useful in this case:

If you want to run EIGRP on a specific interface , then use network command with the wild card mask .
E.g Suppose you hav ethree interface with address 1.1.1.1 , 1.1.2.1 , 1.1.3.1 with /24 mask each. You colud just use classfull network command with 1.0.0.0 and this would enable eigrp on all interface that start with 1 . And If you don't want your network to learn 1.1.2.1 address through eigrp , in that case your use wildcard mask . Network 1.1.1.0 0.0.0.255 and 1.1.3.0 0.0.0.255 . In this manner EIGRP get enable on all interface except 1.1.2.1 . Hope this helps you

Wildcards are required for OSPF.

If any of can help me clear up my PT Lab questions that would be great.

luberguilarte

You wrong , 0.0.0.252 is nothing in the cisco world , you mean 255.255.255.252 if you want to apply that subnet mask to wild-card it will be 0.0.0.3.

sizeon

Thats what i meant. 255.255.255.252 is the same as 0.0.0.3

Roguetadhg