Basic distribute-list question

[news2010a]

Hi,

If you see on the attached diagram,

according to an exercise I am doing I understand that RTC Router will not

receive 10.0.0.0 in its routing table.

Is that happening because the 'access-list 10 permit 192.168.10 0.0.0.255' permits advertisements for 192.168.10.0/24 goes through,

but there is an implicit deny that would 'block' 10.0.0.0 from going to Router RTC ? Is that the reason why RTC would not have 10.0.0.0 on its routing table ?

[rajeshc]

hi

permit the network 10.0.0.0/8 on the RTC.Becz as per ur config. 10.0.0.0 is deny,So u have to permit this network.pls update once done.

[news2010a]

Rajeshc, you mean it is a deny for 10.0.0.0/8 because it is getting an implicit deny, right ?

That means that as a generic rule, as soon as I implement a distribute-list (which uses an access-list) I should list all networks I want to be permitted there, otherwise they would be denied ?

Thanks.

[Adam Frederick]

You are correct!!

RTC should only see 192.168.10.0/24 because it is the only network permitted in the ACL 10. The distribute-list only applies to EIGRP updates sent out S0/0 on RTB, so RTA should have a complete view of the EIGRP topology & RTC will only have information for the 192.168.10.0/24 network. The key in the distribute-list here is the direction it applies to.

[Richard Burts · Accepted solution]

Marlon

Yes there is an implicit deny which will deny 10.0.0.0/8. And yes as soon as you implement a distribute-list which uses a standard access-list you should have permit statements for each network that you want to be advertised, otherwise they will be denied.

HTH

Rick

[rajeshc]

yes u r right.

[news2010a]

Thanks !!! You guys are amazing !