[NTLUG:Discuss] Remote Syslog help needed

Michael Barnes barnmichael at gmail.com
Sun Aug 30 22:32:57 CDT 2009


I have an appliance that can send its logs to a remote log server.  I have a
Centos4 box I am trying to capture the logs with.  But, it doesn't work.
Here is a section of a tcpdump.

22:19:40.011704 IP (tos 0x0, ttl  47, id 30032, offset 0, flags [none],
proto: UDP (17), length: 96) atlas.srn.loc.syslog > bridge.srn.loc.syslog:
SYSLOG, length: 68
        Facility local0 (16), Severity notice (5)
        Msg: ATLAS 830[ADTRAN]:L2-Formatted|5|3|Sent = Sapi:00[|syslog]

22:19:40.011714 IP (tos 0xc0, ttl  64, id 43329, offset 0, flags [none],
proto: ICMP (1), length: 124) bridge.srn.loc > atlas.srn.loc: ICMP host
bridge.srn.loc unreachable - admin prohibited, length 104
        IP (tos 0x0, ttl  47, id 30032, offset 0, flags [none], proto: UDP
(17), length: 96) atlas.srn.loc.syslog > bridge.srn.loc.syslog: SYSLOG,
length: 68        Facility local0 (16), Severity notice (5)
        Msg: ATLAS 830[ADTRAN]:L2-[|syslog]

22:19:40.012375 IP (tos 0x0, ttl  47, id 30033, offset 0, flags [none],
proto: UDP (17), length: 86) atlas.srn.loc.syslog > bridge.srn.loc.syslog:
SYSLOG, length: 58
        Facility local0 (16), Severity notice (5)
        Msg: ATLAS 830[ADTRAN]:L2-Formatted|5|3|       Ctl:SAB[|syslog]

22:19:40.012382 IP (tos 0xc0, ttl  64, id 43330, offset 0, flags [none],
proto: ICMP (1), length: 114) bridge.srn.loc > atlas.srn.loc: ICMP host
bridge.srn.loc unreachable - admin prohibited, length 94
        IP (tos 0x0, ttl  47, id 30033, offset 0, flags [none], proto: UDP
(17), length: 86) atlas.srn.loc.syslog > bridge.srn.loc.syslog: SYSLOG,
length: 58
        Facility local0 (16), Severity notice (5)
        Msg: ATLAS 830[ADTRAN]:L2-[|syslog]


You can see atlas sending a log entry to bridge.  It looks like bridge is
rejecting it due to a prohibition of ICMP traffic.

Here are the iptables:

[root at bridge ~]# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
RH-Firewall-1-INPUT  all  --  anywhere             anywhere

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
RH-Firewall-1-INPUT  all  --  anywhere             anywhere

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Chain RH-Firewall-1-INPUT (2 references)
target     prot opt source               destination
ACCEPT     all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere
ACCEPT     icmp --  anywhere             anywhere            icmp any
ACCEPT     esp  --  anywhere             anywhere
ACCEPT     ah   --  anywhere             anywhere
ACCEPT     udp  --  anywhere             224.0.0.251         udp dpt:mdns
ACCEPT     udp  --  anywhere             anywhere            udp dpt:ipp
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:ipp
ACCEPT     all  --  anywhere             anywhere            state
RELATED,ESTABLISHED
ACCEPT     udp  --  10.113.35.150        anywhere            udp spt:ntp
ACCEPT     udp  --  anywhere             anywhere            state NEW udp
dpt:ntp
ACCEPT     tcp  --  anywhere             anywhere            state NEW tcp
dpt:ssh
REJECT     all  --  anywhere             anywhere            reject-with
icmp-host-prohibited


I have a suspicion that last line about "reject-with icmp-host-prohibited"
might be part of my problem.  But I'm rusty with iptables and don't know how
to fix it if it needs fixing.

Another concern is if it is actually listening for remote logs.  Here is
netstat results.

[root at bridge ~]# netstat -ln
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address
State
tcp        0      0 0.0.0.0:908                 0.0.0.0:*
LISTEN
tcp        0      0 0.0.0.0:111                 0.0.0.0:*
LISTEN
tcp        0      0 127.0.0.1:631               0.0.0.0:*
LISTEN
tcp        0      0 127.0.0.1:25                0.0.0.0:*
LISTEN
tcp        0      0 :::22                       :::*
LISTEN
udp        0      0 0.0.0.0:32768               0.0.0.0:*
udp        0      0 0.0.0.0:514                 0.0.0.0:*
udp        0      0 0.0.0.0:902                 0.0.0.0:*
udp        0      0 0.0.0.0:905                 0.0.0.0:*
udp        0      0 0.0.0.0:67                  0.0.0.0:*
udp        0      0 0.0.0.0:5353                0.0.0.0:*
udp        0      0 0.0.0.0:111                 0.0.0.0:*
udp        0      0 0.0.0.0:631                 0.0.0.0:*
udp        0      0 10.113.35.100:123           0.0.0.0:*
udp        0      0 10.33.8.22:123              0.0.0.0:*
udp        0      0 127.0.0.1:123               0.0.0.0:*
udp        0      0 0.0.0.0:123                 0.0.0.0:*
udp        0      0 :::32769                    :::*
udp        0      0 :::5353                     :::*
udp        0      0 fe80::20e:cff:fedc:f479:123 :::*
udp        0      0 fe80::211:11ff:fe6f:123     :::*
udp        0      0 ::1:123                     :::*
udp        0      0 :::123                      :::*
raw        0      0 0.0.0.0:1                   0.0.0.0:*
7
Active UNIX domain sockets (only servers)
Proto RefCnt Flags       Type       State         I-Node Path
unix  2      [ ACC ]     STREAM     LISTENING     7538
@/var/run/hald/dbus-Eb2j7rE2qL
unix  2      [ ACC ]     STREAM     LISTENING     6203
/var/run/audit_events
unix  2      [ ACC ]     STREAM     LISTENING     6571
/var/run/dbus/system_bus_socket
unix  2      [ ACC ]     STREAM     LISTENING     6798   /var/run/pcscd.comm
unix  2      [ ACC ]     STREAM     LISTENING     6951
/var/run/acpid.socket
unix  2      [ ACC ]     STREAM     LISTENING     6994
/var/run/cups/cups.sock
unix  2      [ ACC ]     STREAM     LISTENING     7496
/var/run/avahi-daemon/socket
unix  2      [ ACC ]     STREAM     LISTENING     7345   /dev/gpmctl
unix  2      [ ACC ]     STREAM     LISTENING     7537
@/var/run/hald/dbus-4rWrcHMzPP


I notice the state is not set to listen for port 514, for syslog.  Could I
not have syslog configured correctly?

[root at bridge ~]# cat /etc/syslog.conf
# Log all kernel messages to the console.
# Logging much else clutters up the screen.
#kern.*                                                 /dev/console

# Log anything (except mail) of level info or higher.
# Don't log private authentication messages!
*.info;mail.none;news.none;authpriv.none;cron.none
/var/log/messages

# The authpriv file has restricted access.
authpriv.*                                              /var/log/secure

# Log all the mail messages in one place.
mail.*                                                  -/var/log/maillog


# Log cron stuff
cron.*                                                  /var/log/cron

# Everybody gets emergency messages
*.emerg                                                 *

# Save news errors of level crit and higher in a special file.
uucp,news.crit                                          /var/log/spooler

# Save boot messages also to boot.log
local7.*                                                /var/log/boot.log

# If they show up, save Atlas log
local0.*                                                /var/log/atlas

#
# INN
#
news.=crit                                        /var/log/news/news.crit
news.=err                                         /var/log/news/news.err
news.notice                                       /var/log/news/news.notice
[root at bridge ~]#


Any ideas appreciated.

Michael


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