Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

failing IP communication across the network with 3750x


I'm facing a very odd problem. A week ago I've installed a 3750x on a client.
 On it, was connected, a Lan2Lan fiber channel(with IP associated directly to 
 the interface) and a MPLS link(over a Cisco 2901) interconnecting a branch, 
 and several HP v1910 L2 swtiches.

By the day of the activation, everything works great. I have at this first moment, 
configured static routes with IP SLA on the L2L link and, with higher cost on the 
MPLS due the larger bandwidth of the L2L. It worked very well, and the tests of 
redundancy were ok.

My problems started a couple of days after. First, I've lost the IP communication 
with the L2 switches from the stations, but, from the 3750x, they still were 
accessible(both telnet and ping).

And now, there's another problem. Because of a previous design, there are two 
gateways configured across the network, all the stations and some servers, 
use as the default gateway the IP, and several servers and other 
appliances where configured with the gateway So, as a workaround, 
I had configured both address on the 3750x, the as primary IP 
and the as secondary IP, both are on the VLAN 1 yet, as all the 
devices. All the stations, servers and appliances are configured with 
this /16 mask. And, it is working.

The problem is, every time that the communications between the branches 
is changed from one link to the another, on some servers and appliances, after the IP SLA 
take away the route, the communications only occurs if I manually change the 
default gateway on the servers/appliance to the other IP, and, get back to the 
previous one.

Does anyone saw something like that?

Everyone's tags (6)
CreatePlease login to create content