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Omnix_TIMS_4122's avatar
Omnix_TIMS_4122
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Jan 13, 2015

Health monitor

Hi,   I have created health monitor on next-hop router as HTTP monitor since the connected router is blocking ICMP protocol. What I have done here: 1.Create monitor type as HTTP with Send String (...
Omnix_TIMS_4122's avatar
Omnix_TIMS_4122
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Jan 14, 2015

Hi ,

 

Thanks all for your replys. I just need to say that when i use send GET /\r\n\r\n and receive string is HTTP/1.1 and do tcpdump I see:

 

IP 10.18.231.245.7995 > 10.18.231.241.http: S 912105303:912105303(0) win 5840 out slot2/tmm1 lis= flowtype=130 flowid=CD17940 peerid=CCD4D00 conflags=626 inslot=0 inport=0 haunit=0 peerremote=00000000:00000000:0000FFFF:0A12E7F5 peerlocal=00000000:00000000:0000FFFF:0A12E7F1 remoteport=38785 localport=80 proto=0 vlan=2001

 

Can you see anything useful here?

 

Ed_Summers's avatar
Ed_Summers
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Jan 16, 2015
Do you get anything else in the tcpdump? I only see one SYN here, normally there will be multiple attempts before the client gives up. Running under the assumption that you're not receiving a reply (SYN ACK) from the destination, and both hosts appear to be on the same network, I'd first look at the destination. My first two checks would be to verify that the destination indeed has an HTTP server running, and it does not have any access-controls blocking your monitor attempts. Let's go back to Michael J's suggestion to use curl. Likely you'll get nothing back (or a "cannot connect" or "connection refused"). If that is the case, then the device is not accepting requests - either the service isn't running or an access-control on the device is blocking your monitor. You'll need to shift troubleshooting to the device at that point. You can also try 'curl -kvv https://10.18.231.241' to see if they're running an HTTPS server instead of HTTP. Good luck! -Ed