Forum Discussion

Tushar_129950's avatar
Tushar_129950
Icon for Nimbostratus rankNimbostratus
Dec 22, 2015

Why LTM VS not responding to SYN

Hey All,

 

I have setup VS on my lab LTM VE, VS is UP, responds to ping from client, however doesn't respond to SYN (as per tcpdump) upon accessing VS from client browser.

 

Any ideas?

 

Thanks, Tushar.

 

application delivery
LTM

3 Replies

  • nathe's avatar
    nathe
    Icon for Cirrocumulus rankCirrocumulus
    Dec 22, 2015
    I think the DC community would need a bit more info to help e.g VS details, assigned Profiles, VS status etc.
  • Tushar_129950's avatar
    Tushar_129950
    Icon for Nimbostratus rankNimbostratus
    Dec 22, 2015
    sure Nathan, VS is Standard VS with TCP, HTTP profile, SNAT & Auto-Last Hop enabled. VIP status is also up. Ingress VLAN: 57 (Virtual Servers), Egress VLAN: 58 (Web Server) I think this might be vlan tagging issue, as incoming packets not tagged with vlan id 57, just to note though ping is working.
  • crodriguez's avatar
    crodriguez
    Ret. Employee
    Dec 30, 2015

    What do local traffic statistics for the virtual server show on the BIG-IP system? Is the virtual server even receiving the SYN packet? Do you see any dropped packets in the Traffic Summary statistics?