topic Re: ERS4850 Web Server disabling itself in ExtremeSwitching (VSP/Fabric Engine)

ERS4850 Web Server disabling itself

rumanchu — Thu, 02 May 2019 04:29:37 GMT

I am having an irritating issue with one of my ERS4850 stacks: every time I want to connect to it via the internal web server, I have to SSH to it and disable the web server (using web-server disable) then re-enable it (via web-server enable) in order to connect. I do a wr mem after I do this, then when I try to connect to the switch later in the day or on a following day I need to go through the same process again, even though I can confirm via the CLI that the web server is enabled.

The switch is running v5.12.2.011, and this is the only switch that I am having this issue with. Is there something obvious that I'm missing here?

Re: ERS4850 Web Server disabling itself

Roger_Gravelle — Thu, 02 May 2019 05:12:31 GMT

It seems like possibly previous sessions not closing TCP ports properly which are then getting exhausted which then gets cleared when you disable/enable the web-server.

When you SSH into the switch try running the 'show ip netstat' command to see if there is an excessive number of connections in use for the web-server (port 80 or 443). If so, take a look at the foreign address to see if it seems logical. Do this before you disable/enable the web-server.

Example (from a ERS4500 switch running older code but it should look similar)
This was run right after connecting to the web-interface from my PC. These closed after about a minute of inactivity.
.56 is the 4500
.150 is my PC
Of course if you are using HTTPS it will be port 443

code:

4524GT-PWR#show ip netstat
Proto Recv-Q Send-Q Local Address        Foreign Address      State
----- ------ ------ --------------------- --------------------- -----------
TCP       0     0 0.0.0.0.23           0.0.0.0.0            LISTEN
TCP       0     0 0.0.0.0.80           0.0.0.0.0            LISTEN
TCP       0     3 192.168.40.56.23     192.168.40.150.58448 ESTABLISHED
TCP       0     0 192.168.40.56.80     192.168.40.150.58637 TIME_WAIT
TCP       0     0 192.168.40.56.80     192.168.40.150.58638 TIME_WAIT
TCP       0     0 192.168.40.56.80     192.168.40.150.58641 ESTABLISHED
TCP       0     0 192.168.40.56.80     192.168.40.150.58642 ESTABLISHED
TCP       0     0 192.168.40.56.80     192.168.40.150.58643 ESTABLISHED
TCP       0     0 192.168.40.56.80     192.168.40.150.58645 ESTABLISHED
TCP       0     0 192.168.40.56.80     192.168.40.150.58646 ESTABLISHED
TCP       0     0 192.168.40.56.80     192.168.40.150.58647 ESTABLISHED
UDP       0     0 0.0.0.0.161          0.0.0.0.0
UDP       0     0 0.0.0.0.0            0.0.0.0.0
UDP       0     0 0.0.0.0.0            0.0.0.0.0
UDP       0     0 0.0.0.0.0            0.0.0.0.0

Re: ERS4850 Web Server disabling itself

rumanchu — Sat, 04 May 2019 03:39:38 GMT

I just attempted to connect via HTTP and was unable to, so I logged in via SSH and ran show ip netstat:

code:

bhrs-28thNorth-edge#sho ip netstat
Proto Recv-Q Send-Q  Local Address         Foreign Address       State      
----- ------ ------  --------------------- --------------------- -----------
TCP        0      0  0.0.0.0.22            0.0.0.0.0             LISTEN     
TCP        0    104  11.23.102.5.22        11.23.40.83.1088      ESTABLISHED
UDP        0      0  0.0.0.0.161           0.0.0.0.0            
UDP        0      0  0.0.0.0.0             0.0.0.0.0            
UDP        0      0  0.0.0.0.0             0.0.0.0.0            
----------------------------------------------------------------------------
Proto Port  Service
----- ----- -------
TCP   22    SSH    
UDP   161   SNMP

That foreign address is the IP of the computer that I'm using to SSH to the switch.