troubleshooting Question

Wild Card Mask

Avatar of jskfan
jskfanFlag for Cyprus asked on
RoutersSwitches / HubsNetworking
14 Comments2 Solutions497 ViewsLast Modified:
Network
In the topology above , I have EIGRP configured on both routers.
I have advertised all the networks to EIGRP

these are the interfaces in R2:
R2(config-router)# do show ip interface bri
Interface                  IP-Address      OK? Method Status                Protocol
FastEthernet0/0            192.168.12.2    YES manual up                    up      
FastEthernet0/1            unassigned      YES unset  administratively down down    
FastEthernet1/0            unassigned      YES unset  administratively down down    
FastEthernet1/1            unassigned      YES unset  administratively down down    
Loopback0                  172.16.0.2      YES manual up                    up      
Loopback1                  172.16.1.2      YES manual up                    up      
Loopback2                  172.16.2.2      YES manual up                    up      
Loopback3                  172.16.3.2      YES manual up                    up      
R2(config-router)#

in R2 , when I advertise R2(config-router)#network 172.16.0.0 0.0.3.255
I do not get any error, and all 172.x.x.x networks will show up in R1 routing table:

R1#sh ip route  eigrp 

Gateway of last resort is not set

      172.16.0.0/24 is subnetted, 4 subnets
D        172.16.0.0 [90/156160] via 192.168.12.2, 00:02:02, FastEthernet0/0
D        172.16.1.0 [90/156160] via 192.168.12.2, 00:02:02, FastEthernet0/0
D        172.16.2.0 [90/156160] via 192.168.12.2, 00:02:02, FastEthernet0/0
D        172.16.3.0 [90/156160] via 192.168.12.2, 00:02:02, FastEthernet0/0
R1#

but if I try different wild card mask I get error  :
R2(config-router)#network 172.16.0.0 0.0.4.255
%EIGRP: Invalid mask (discontiguous)

but if I try these wild card masks one a time after Negating one of them , it will work:
R2(config-router)#network 172.16.0.0 0.0.1.255
R2(config-router)#network 172.16.0.0 0.0.0.255  

***So the ones that worked (one a time) are:
R2(config-router)#network 172.16.0.0 0.0.1.255
R2(config-router)#network 172.16.0.0 0.0.0.255  
R2(config-router)#network 172.16.0.0 0.0.3.255

the :172.16.0.0 0.0.2.255 ,172.16.0.0 0.0.4.255,172.16.0.0 0.0.5.255........172.16.0.0 0.0.254.255

I get this error :%EIGRP: Invalid mask (discontiguous)

Any idea why  ?

Thank you
SOLUTION
Mitul Prajapati
Systems Administrator

Our community of experts have been thoroughly vetted for their expertise and industry experience.

Join our community to see this answer!
Unlock 2 Answers and 14 Comments.
Start Free Trial
Learn from the best

Network and collaborate with thousands of CTOs, CISOs, and IT Pros rooting for you and your success.

Andrew Hancock - VMware vExpert
See if this solution works for you by signing up for a 7 day free trial.
Unlock 2 Answers and 14 Comments.
Try for 7 days

”The time we save is the biggest benefit of E-E to our team. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange.

-Mike Kapnisakis, Warner Bros