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Forum Discussion

MAbbas's avatar
MAbbas
Icon for Cirrus rankCirrus
Jun 29, 2018

2 ips with 1 Mac address

hi i am seeing 2 ip addresses associated with 1 MAC - address the F5 has just 1 interface and 1 vlan (Azure deployment) 12:34:56:78:9a:bc net arp 10.8.XX.42(second f5 in device group) mac-address 12:34:56:78:9a:bc net arp 10.8.XX.1(gateway ip address) mac-address

 

and that is causing the return traffic to be seen with different MAC addresses AND THAT is causing delays in javascript download - can you please help 16:08:21.305514 00:0d:3a:d0:df:93 > 12:34:56:78:9a:bc, 10.8.XX.40.4540 > 10.8.XY.128.443: Flags [P.], cksum 0xf641 (correct), seq 16:08:21.310428 40:01:7a:af:fc:2f > 00:0d:3a:d0:df:93, 10.8.XY.128.443 > 10.8.XX.40.4540: Flags [.], cksum 0xc3a3 (correct), seq

 

application delivery
BIG-IP
LTM

2 Replies

  • MAbbas's avatar
    MAbbas
    Icon for Cirrus rankCirrus
    Jun 30, 2018

    12:34:56:78:9a:bc net arp 10.8.XX.42(second f5 in device group)

     

    12:34:56:78:9a:bc net arp 10.8.XX.1(gateway ip address)

     

  • boneyard's avatar
    boneyard
    Icon for MVP rankMVP
    Jul 07, 2018

    in general there is nothing weird with multiple IP addresses and 1 MAC address. as long as that MAC address belong to one device / interface.

     

    but you are working on a cloud service so MAC addresses are often manipulated by the cloud provider. on cloud services i usually "ignore" layer 2 and lower. and i seriously doubt the MAC address situation is causing a slow javascript download (but not other things?).

     

    the test seems quite easy, shutdown the second BIG-IP and see if the situation changes with only one MAC address.