08-23-2013 06:35 AM - edited 03-07-2019 03:05 PM
I've two 4500X configured in VSS mode and I use it as my main gateway.
I try to ping 192.168.125.247 (vlan 125) from a machine in vlan 120 (192.168.120.164 / 255.255.254.0 / 192.168.120.254 ) and the ping is not working.
The 4500X cluster is the gateway for these two vlans :
interface Vlan120
ip address 192.168.120.252 255.255.254.0
standby version 2
standby 1 ip 192.168.120.254
standby 1 priority 110
standby 1 preempt
interface Vlan125
ip address 192.168.125.252 255.255.255.0
standby version 2
standby 1 ip 192.168.125.254
standby 1 priority 110
standby 1 preempt
I can see an arp entry in the 4500X :
gw01#sh arp 192.168.125.247
Protocol Address Age (min) Hardware Addr Type Interface
Internet 192.168.125.247 32 00e0.8615.8775 ARPA Vlan125
The mac address is correct but I can not see it in the mac address-table :
gw01#sh mac address-table address 00e0.8615.8775
No entries present.
if I try this command on my 4500X, it's working :
gw01#ping 192.168.125.247 source 192.168.120.252
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.125.247, timeout is 2 seconds:
Packet sent with a source address of 192.168.120.252
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/11/36 ms
Then I can see the mac in the address-table :
gw01a#sh mac address-table address 00e0.8615.8775
Unicast Entries
vlan mac address type protocols port
---------+---------------+--------+---------------------+-------------------------
125 00e0.8615.8775 dynamic ip,ipx,assigned,other Port-channel13
Now, I can also ping from my machine in vlan 120 but after 5 minutes, this entry will disapear and I will not be able to ping it from my machine in the vlan 120.
If I clear the arp entry it's also working for 5 minutes...
Any idea ?