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Amafsha1
Explorer

Redundant prefix-list?

Sorry for the dumb question, but is this prefix-list just allowing everything at the end?  so there is no point in specifying subnets before the last statment?

 

ip prefix-list eigrp-to-bgp seq 100 permit 0.0.0.0/0
ip prefix-list eigrp-to-bgp seq 120 permit 10.60.225.0/24
ip prefix-list eigrp-to-bgp seq 140 permit 10.124.10.0/24
ip prefix-list eigrp-to-bgp seq 240 permit 172.28.250.0/24
ip prefix-list eigrp-to-bgp seq 310 permit 192.168.12.0/24
ip prefix-list eigrp-to-bgp seq 320 permit 0.0.0.0/0 le 32

!

route-map eigrp-to-bgp permit 100
match ip address prefix-list eigrp-to-bgp

!

2 ACCEPTED SOLUTIONS

Accepted Solutions
Georg Pauwen
VIP Expert

Hello,

 

indeed, 0.0.0.0/0 le 32 would allow all routes...making all your previous lines obsolete...

View solution in original post

Rafael Carvallo
Beginner

Hi,

 

Indeed 

ip prefix-list eigrp-to-bgp seq 320 permit 0.0.0.0/0 le 32

is basically permitting all, basically this last rule reads as:

 

"permit anything from  0.0.0.0/0 (basically all ips) with a mask from 0 to less or equal than 32 (all possible subnets)"

 

If you want to avoid other subnets not explicitly added to the prefix-list, change the permit statement to a deny one. 

 

There are no dumb questions btw! it's better to always ask when unsure 

View solution in original post

4 REPLIES 4
Georg Pauwen
VIP Expert

Hello,

 

indeed, 0.0.0.0/0 le 32 would allow all routes...making all your previous lines obsolete...

View solution in original post

Rafael Carvallo
Beginner

Hi,

 

Indeed 

ip prefix-list eigrp-to-bgp seq 320 permit 0.0.0.0/0 le 32

is basically permitting all, basically this last rule reads as:

 

"permit anything from  0.0.0.0/0 (basically all ips) with a mask from 0 to less or equal than 32 (all possible subnets)"

 

If you want to avoid other subnets not explicitly added to the prefix-list, change the permit statement to a deny one. 

 

There are no dumb questions btw! it's better to always ask when unsure 

View solution in original post

Thank you very much.  So than what is the first line saying?

 

ip prefix-list eigrp-to-bgp seq 100 permit 0.0.0.0/0

Hi, this one is only permitting the default route, since you didn't add the "le or ge" words, basically reads as:

 

Permit Route 0.0.0.0 with mask 0.0.0.0 exactly

 

Thus allowing only this specific prefix.