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[LDM #NTH-493887]: ldmping one way only



Donna,

The results of your using telnet(1) from inside the campus security perimeter
(via a VPN) and from outside it appear to be definitive: The security perimeter
doesn't allow TCP connections to be initiated from within the perimeter to port
388 outside the perimeter.

> My thoughts are that ldm-relay0 has been doing all of the work and this
> connection problem has been with us on ldm-relay1. I have my tech checking
> on the firewall rules. I can tell you that the iptables (on all our LDM
> machines) already have this in the iptables:
> 
> -A INPUT -p tcp -m multiport --ports 388 -m comment --comment "100 open
> port 388 for ldm" -j ACCEPT
> 
> One *important* note: ldm-relay1 is outside of the A&M firewall and ldm3 is
> inside the A&M firewall. *Taimur*, can you tell me if port 388 is open
> through the A&M firewall? This was set up a long time ago but there has
> been a change in leadership in A&M's IT so who knows if this got changed
> without our notice.
> 
> Our sys admin has not installed telnet (on purpose, I believe). I can use
> ping and ldmping.
> 
> After getting up a VPN connection to campus, I can get this from my Mac
> laptop:
> 
> donna-cotes-macbook-pro:~ donnacote$ telnet ldm-relay1.tamu.edu 388
> Trying 165.91.55.27...
> telnet: connect to address 165.91.55.27: Operation timed out
> telnet: Unable to connect to remote host
> donna-cotes-macbook-pro:~ donnacote$ telnet ldm3.tamu.edu 388
> Trying 128.194.76.166...
> Connected to ldm3.tamu.edu.
> Escape character is '^]'.
> ^]
> telnet> ^Cdonna-cotes-macbook-pro:~ donnacote$
> 
> Now, I alto notice this. When I turn off my VPN connection to campus, I get
> this:
> 
> donna-cotes-macbook-pro:~ donnacote$ telnet ldm-relay1.tamu.edu 388
> Trying 165.91.55.27...
> Connected to ldm-relay1.tamu.edu.
> Escape character is '^]'.
> ???Connection closed by foreign host.
> donna-cotes-macbook-pro:~ donnacote$ telnet ldm3.tamu.edu 388
> Trying 128.194.76.166...
> telnet: connect to address 128.194.76.166: Operation timed out
> telnet: Unable to connect to remote host
> donna-cotes-macbook-pro:~ donnacote$
> 
> FYI:
> 
> > [root@ldm-relay1 ~]# iptables --list
> > Chain INPUT (policy ACCEPT)
> > target     prot opt source               destination
> > ACCEPT     icmp --  anywhere             anywhere            /* 000 accept
> > all icmp */
> > ACCEPT     all  --  anywhere             anywhere            /* 001 accept
> > all to lo interface */
> > ACCEPT     all  --  anywhere             anywhere            /* 002 accept
> > related established rules */ state RELATED,ESTABLISHED
> > ACCEPT     tcp  --  anywhere             anywhere            multiport
> > dports ssh /* 003 accept new ssh */ state NEW
> > ACCEPT     tcp  --  anywhere             anywhere            multiport
> > dports ndmp /* 100 allow webmin access */
> > ACCEPT     tcp  --  anywhere             anywhere            multiport
> > ports zabbix-agent /* 100 allow zabbix-agent */
> > ACCEPT     tcp  --  anywhere             anywhere            multiport
> > ports unidata-ldm /* 100 open port 388 for ldm */
> > ACCEPT     tcp  --  anywhere             anywhere            multiport
> > dports sunrpc /* 101 portmapper tcp */
> > ACCEPT     udp  --  anywhere             anywhere            multiport
> > dports sunrpc /* 102 portmapper udp */
> > ACCEPT     tcp  --  anywhere             anywhere            multiport
> > dports 32803 /* 103 lockd tcp */
> > ACCEPT     udp  --  anywhere             anywhere            multiport
> > dports filenet-rpc /* 104 lockd udp */
> > DROP       all  --  anywhere             anywhere            /* 999 deny
> > all */
> >
> > Chain FORWARD (policy ACCEPT)
> > target     prot opt source               destination
> > DROP       all  --  anywhere             anywhere            /* 999 deny
> > all FORWARD */
> >
> > Chain OUTPUT (policy ACCEPT)
> > target     prot opt source               destination
> > [root@ldm-relay1 ~]# iptables --list-rules
> > -P INPUT ACCEPT
> > -P FORWARD ACCEPT
> > -P OUTPUT ACCEPT
> > -A INPUT -p icmp -m comment --comment "000 accept all icmp" -j ACCEPT
> > -A INPUT -i lo -m comment --comment "001 accept all to lo interface" -j
> > ACCEPT
> > -A INPUT -m comment --comment "002 accept related established rules" -m
> > state --state RELATED,ESTABLISHED -j ACCEPT
> > -A INPUT -p tcp -m multiport --dports 22 -m comment --comment "003 accept
> > new ssh" -m state --state NEW -j ACCEPT
> > -A INPUT -p tcp -m multiport --dports 10000 -m comment --comment "100
> > allow webmin access" -j ACCEPT
> > -A INPUT -p tcp -m multiport --ports 10050 -m comment --comment "100 allow
> > zabbix-agent" -j ACCEPT
> > -A INPUT -p tcp -m multiport --ports 388 -m comment --comment "100 open
> > port 388 for ldm" -j ACCEPT
> > -A INPUT -p tcp -m multiport --dports 111 -m comment --comment "101
> > portmapper tcp" -j ACCEPT
> > -A INPUT -p udp -m multiport --dports 111 -m comment --comment "102
> > portmapper udp" -j ACCEPT
> > -A INPUT -p tcp -m multiport --dports 32803 -m comment --comment "103
> > lockd tcp" -j ACCEPT
> > -A INPUT -p udp -m multiport --dports 32769 -m comment --comment "104
> > lockd udp" -j ACCEPT
> > -A INPUT -m comment --comment "999 deny all" -j DROP
> > -A FORWARD -m comment --comment "999 deny all FORWARD" -j DROP
> > [root@ldm-relay1 ~]#


Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: NTH-493887
Department: Support LDM
Priority: Normal
Status: Closed
===================
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