The 2950 is a switch, i.e a Layer-2 device. For its normal operations, it doesn't care about ARP, which maps L3 to L2 addresses.
So to troubleshoot your problem, consider what the switch is doing that is related to Layer 3 and above. Does it do network management, ping, Telnet? What does the switch use for a default gateway when it does these upper-layer functions? Is that default gateway router doing Proxy ARP and replying with its MAC address for devices on the other side of it? What are the MAC and IP addresses in this mysterious ARP cache that you are worried about? With some knowledge or your addressing scheme, you should be able to figure out what's going on. Priscilla Cliff Cliff wrote: > > Dear all, > > For my company, there are two equipment rooms, one is in > upstair ad one is in downstair. So we are using fiber > connecting these two floor equipments by using Cisco 2950 > (which having 2 Fiber port) in both upstair and downstair. > > In cisco 2950, there are 24 ports, for some reason, I need to > set 12 ports for VLAN1 (IP address A.B.C.0/24) andb 12 ports > for VLAN2(E.F.G.0/24) in upstair cisco 2950. Note that port 25 > is also VLAN1 and port 26 is VLAN2. The same applied to > downstair cisco 2950 (Now we have two fibers connecting to > upstair and downstair cisco 2950). The result why connected > like this is we want to seperate the traffic for VLAN1 and VLAN2. > > The config is like this > > upstair and downstair cisco 2950 switch config > ============================================== > Port 1 to port 12: > > under interface FastEthernet0/1 to 0/12 - no special config > (default) > > Port 13 to port 24: > > under interface FastEthernet0/13 to 0/24 - adding "switchport > access vlan 2" > > Assign ip address for upstair cisco 2950: > > interface VLAN1 > ip address A.B.C.1 255.255.255.0 > > Assign ip address for downstair cisco 2950: > > interface VLAN1 > ip address A.B.C.2 255.255.255.0 > > But when I issue a command show arp, I see very strange > situation. > > Actually from my knowledge, the arp table should contains only > local arp table. But I find that there are some external > address on my arp table. WHY? Really not understanding? Is my > config for VLAN is wrong? > > Also when I issue a command "show vlan brief", I get the > following output: > > VLAN Name Status Ports > ---- -------- --------- ------ > 1 default active Fa0/1,Fa0/2, ... > ,Fa0/12,Fa0/25 > 2 VLAN0002 active Fa0/13,Fa0/14, ... , Fa0/24, > Fa0/26 > 1002 fddi-default active > 1003 token-ring-default active > 1004 fddinet-default active > 1005 trnet-default active > > which I believe that I am not setting wrong for VLAN. Any > comment or suggestion? Thx! > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=58477&t=58404 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
