In remote location, the 3750x core switch is configured in stack. Six department's stacked Access switch is connecting to the 3750x switch with fiber as uplink, which is configured again in trunk port-channel.
As I mentioned in Summary,We have more than 40 location( cisco 2911), which are all connecting to our central HO location on cisco 3845. In most of these remote location we are using Core Switch as 3750x (Stack) with access switch as WS-C2960X-24PS-L (stack), where Core connects directly to Access on Trunk uplink and to local WAN router with IP. Routing Protocol used is EIGRP.
I am recently getting the error as "One or more, more specific prefixes could not be programmed into TCAM and are being covered by a less specific prefix, and the packets may be software forwarded" . I understood that the TCAM error is depended on the SDM Template, I cross checked it and understood that we are using "desktop default" template as shown in below command. And as well I checked the IP summary route and the command is below as well.
CoreSwitch3750x-Stack#sh sdm prefer
The current template is "desktop default" template.
The selected template optimizes the resources in
the switch to support this level of features for
8 routed interfaces and 1024 VLANs.
number of unicast mac addresses: 6K
number of IPv4 IGMP groups + multicast routes: 1K
number of IPv4 unicast routes: 8K
number of directly-connected IPv4 hosts: 6K
number of indirect IPv4 routes: 2K
number of IPv4 policy based routing aces: 0
number of IPv4/MAC qos aces: 0.5K
number of IPv4/MAC security aces: 1K
CoreSwitch3750x-Stack#sh ip route summary
IP routing table name is default (0x0)
IP routing table maximum-paths is 32
Route Source Networks Subnets Replicates Overhead Memory (bytes)
connected 0 32 0 1920 5504
static 0 0 0 0 0
eigrp 1 4 1338 0 107360 230824
internal 38 64516
Total 42 1370 0 109280 300844
From above command I can conclude that I am having nearly 1412 routes, so as a workaround I removed EIGRP on the Core Switch 3750x. And on the WAN router (2911) I have applied a static route pointing to the all the subnets on the Core Switch 3750x. In order for users from various location to reach this particular location, I have redistributed the static route on the WAN router back in to EIGRP. After this changes, the sh ip route summary reported routes has reduced on the core Switch, as shown below
CoreSwitch3750x-Stack#sh ip route summ
IP routing table name is default (0x0)
IP routing table maximum-paths is 32
Route Source Networks Subnets Replicates Overhead Memory (bytes)
connected 0 46 0 2760 7912
static 1 0 0 60 172
eigrp 100 0 0 0 0 0
internal 1 1796
Total 2 46 0 2820 9880
I doubt, Is it a best practice, as I am using redistribution in this site? I will consider redistribution as a last resort as in near future we will have additional location connecting behind this location.
What would have went wrong in this site, as all other location we have the same devices and same setup ? And advise on the best practice for such scenarios.
