Four 6500 connected to each other to form a full mesh. Switches 4 and 7 is running eigrp. A question came up, why didnt it have eigrp on SW 2 & 3 ? Will it still be redundant if link between SW3 and SW4 is removed? If redundancy is working, SW3 should be able to find its way to SW4 via SW7 or SW2, yes?
The config looks:
SW4 eigrp
router eigrp 100
network 192.168.0.0
redistribute static
auto-summary
sh ip route static
S x.x.242.48 [1/0] via x.x.186.10 (pointing to network outside of our LAN)
sh ip route summ
Route Source Networks Subnets Overhead Memory (bytes)
Connected 0 51 3672 7344
static 0 1 72 144
eigrp 400 1 6 504 1008
internal 3 6564
Total 4 58 4248 15060
SW7 eigrp
router eigrp 100
network 192.168.0.0
auto-summary
sh ip route static
“EMPTY”
sh ip route sum
Route Source Networks Subnets Overhead Memory (bytes)
connected 0 51 3264 8160
static 0 0 0 0
eigrp 400 1 7 704 1280
internal 3 3540
Total 4 58 3968 12980
SW 2 and SW 3:
ip route
C 192.168.2.0 is directly connected, Vlan1
S* 0.0.0.0/0 [1/0] via 192.168.2.1 <--this is pointing to SW# 4
SW 2 and SW 3
sh ip route summ
Route Source Networks Subnets Overhead Memory (bytes)
connected 0 1 72 144
static 1 0 72 144
internal 1 2188
Total 2 1 144 2476
Recently, the eigrp was configured to SW 2 and SW 3 as well, it included the “redistribute static” statement. The route for SW2 and SW3 now has the VLANs, 51 or so. Sent ping from a PC to VLAN1 IP of SW3, then link between SW3 and SW4 was disconnected, network connectivity went down for about 20secs, and ping came right back. Thought it was a success. All of a sudden, outside connectivity was lost. Ping within the LAN was successful, but no internet connection.
The eigrp on SW2 and SW3 was removed, and the internet connection came back up. The initial concern was that although there is physical redundancy in place, the other routes may not be known. Hence, eigrp configuration has been attempted for SW2 and SW3. Perhaps the “redistribute static” should have never been configured on SW2 and SW3, SW7 does not have the “redistribute static” statement anyway.
Without eigrp running on SW2 and SW3, does it still have redundancy? For what it’s worth, SW4 and SW7 are both VTP servers. With the current configs, does it still have redundancy? Link redundancy was never tested; it always has been assumed that it works. Later today, with it’s current config, the link redundancy will be tested.
Thoughts? Thanks.
