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Nuno_xzorp's avatar
Nuno_xzorp
Icon for Altostratus rankAltostratus
Sep 12, 2021

Big5 LTM GUI not reachable but can ping

Hi, I'm very new in BIG5, I would like to ask your help, I had a power cut and when the power came up, I wasn't able to access the management GUI but I can ping, also when I tried to ssh, it promps ...
BIG-IP
cloud
LTM
oguzy's avatar
oguzy
Icon for Cirrostratus rankCirrostratus
Sep 12, 2021

Hi Nuno_xzorp,

Although both devices are on the same network, and port 443 listens on the bigip, you could not reach.

Could you please start a tcpdump on your management interface of bigip device, and try to telnet again? I wonder if you see the SYN packet on the tcpdump? 

tcpdump -nni name_of_mgmt_interface port 443
Nuno_xzorp's avatar
Nuno_xzorp
Icon for Altostratus rankAltostratus
Sep 13, 2021

Hi oguzy,

I'm not sure what has triggered it, but the mgmt mac-address have changed on the system, since then it started to worki. So before it was 00:94:a1:0c:20:80, but the arp on the switch was mapping the mgmt ip to 00:94:a1:0c:20:82, even clearing arp cache and few port shudowns it stayed the same (I mentioned it on my 2nd post). Not sure what triggered this, so not sure if this is a normal behaviour or if it was some bug, the only thing I did was doing those TCPDUMPS that you suggested, at somepoint I started see the packets. I've captured the following logs from kernel, timestamps more or less at the time when started to work:

Sep 13 21:18:18 F5_STD info kernel: lasthop-ingress-v4: tcp non-syn packet

Sep 13 21:23:46 F5_STD info kernel: device mgmt entered promiscuous mode

Sep 13 21:24:52 F5_STD info kernel: device mgmt left promiscuous mode

if you have any clue of what might have happened let me know. Many thanks for your help!