Signiant Support

No access to agent: "No route to host" Print


Symptoms

Connections to a Linux agent are failing with one of the following:

Can't access agent from manager:
     "Some properties cannot be opened for editing."

Jobs involving this agent fail and the logs show:
     "Error sending the connect command to 'agent_name': No route to host"

dds_cnctst returns:
     "Error sending the connect command to 'agent_name': No route to host"

In addition:
  • the issue is consistent (not intermittent)
  • names resolution is working properly
  • the routing table is OK
  • dds_cnctst from agent to manager is possibly OK
However on the agent, /sbin/iptables -L -n produces text similar to the following:
     Chain INPUT (policy ACCEPT)
     target     prot opt source               destination
     REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited

Resolution

The IP Tables service running on the agent is rejecting connections.  One of the following options can be used to allow connections to the agent:
Temporarily turn off iptables:
     /etc/init.d/iptables save
     /etc/init.d/iptables stop


Or allow the Signiant TCP and UDP ports:
     iptables -A INPUT -m state --state NEW -m tcp -p tcp --dport 49221 -j ACCEPT 
     iptables -A INPUT -m state --state NEW -m udp -p udp --dport 49221:49232 -j ACCEPT