Good Morning,
We are having connectivity problems to some host (PC`s) located inside a network layer 2.
We have a switch cisco 4503 as a CORE and 2950 switchces as access.
The internal ip segment is: 10.160.223.x/16.
The problem is:
- One user with ip address: 10.160.223.12 is connected directly to a switch 2950.
- From the switch core: 4503 we can make ping to this host: 10.160.223.12 but when we ingress the command: sh arp | include 10.160.223.12 does not appear nothing.
- Then, we go to the switch 2950 where is the user directly connected. We can make ping to the host: 10.160.223.12 but when ingress the command: sh arp | include 10.160.223.12 does not appear nothing.
- We useD the command: clear arp-cache at switch 2950 and after that we can see result with the command: sh arp | include 10.160.223.12.
- In that moment in the switch core 4503 appears the message:
000012: *Apr 4 11:44:38.857 GMT: %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking FastEthernet2/22 on VLAN0001. Port consistency restored.
SW4503_CORE1#
The port Fast 2/22 is used to connect using trunk mode to the switch 2950.
We have reviewing some links from CISCO and they talk about:
- bug problem and change of IOS
- ARP storm
- arp attack
We know that these switchesd 2950 are very old and maybe requieres sooner changes for new models,
Can you tell us what is your point of view regard this problem and what solution do you recommend?
Thanking you in advance.
