<html><head></head><body><div>Sounds like a routing problem. ip route will show the defaults. If BOTH are not pointed at each other, nothing happens. Verify with tcpdump on both ends - look for traffic to/from <host></div><div><br></div><div>Host A has nics 1 & 2 (A1 & A2)</div><div>Host B has nics 1 & 2 (B1 & B2)</div><div><br></div><div>Assumption is A1 and B1 are on network 192.168.0.0 and A2 and B2 are on 10.1.1.0. Assumption default route is 192.168.0.0.</div><div><br></div><div>To get those machines to talk on the 10.1.1.0 network, you will need to use explicit IP address and adding a custom name in /etc/hosts is a good idea.</div><div><br></div><div>Also need to verify that the database is listing on the correct IP - ditto for tomcat.</div><div><br></div><div>I just spent _days_ trying to trace a multi-homed network FSCKUP through iptables. Data in on port A never appears anywhere else. tracing it through just showed where it vanished - between PREROUTING RAW and PREROUTING NAT. I feel your pain.</div><div><br></div><div>On Fri, 2018-01-26 at 13:01 -0500, leam hall via Ale wrote:</div><blockquote type="cite" style="margin:0 0 0 .8ex; border-left:2px #729fcf solid;padding-left:1ex"><pre>Using RHEL 6, two hosts (A, B) each with two NICs, Each host has one
NIC on each of two VLANs. Tomcat on Host_A rying to connect to MySQL
on Host_B, port 3306. iptables on Host_B looks open (0.0.0.0) for
TCP/3306.
Host_A_NIC_0 can connect to Host_B_NIC_0 TCP/3306
HOST_A_NIC_1 can NOT connect to HOST_B_NIC_1 TCP/3306.
They are 1 IP off and NIC_1 can ping NIC_1, but not connect TCP/3306.
Thoughts on how to figure out why when iptables looks open?
Leam
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</pre></blockquote><div><span><pre><pre>-- <br></pre>James P. Kinney III
Every time you stop a school, you will have to build a jail. What you
gain at one end you lose at the other. It's like feeding a dog on his
own tail. It won't fatten the dog.
- Speech 11/23/1900 Mark Twain
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