I am running Centos 6.3 and attempting to use snmp v3 to query OID's on this server. Running Paessler's snmp tester 5.1.3 I get a no response from host. I have made sure that my iptables do not have any odd firewall settings. I can verify that snmpd is listening on port 161. I have also made sure that SELinux is fully disabled. I am able to install this on Centos 7.1 without any issue. I have done a tail on the messages in var/log/messages and can see incoming traffic for snmpd. I am stumped and have no idea why this will work on one version of this OS but not another. I wonder if anyone has any suggestions.
Thank you
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I've almost clean installation of OSX Ventura on macbook air m2. I'm runinig some tests and during test initialization I noticed that it waits many times for 2 minutes.
After looking though the code I noticed it's checking whether specific ports are available. What's funny is that it's trying to connect to 0.0.0.0:10389.
netstat -an doesn't show anything listeing on port 10389, but there's still 30s timeout until connection attempt is rejected.
Same if I try telnet 0.0.0.0 10389 or any other port. There's some firewall or something that I can't find that's probably timeouting the connection. But what to search for? It's clean installation. FW is disabled in settings, I uninstalled eset cyber security...
Any ideas? I'm stuck on this for few days already...
I'm trying to get my head around SNMP for a project I'm working on. After I failed miserably getting it to work in my company's network, I set up a simple 3-device network to test things on, consisting of two Windows 10 PCs and a manageable switch between them.
I installed the optional feature "SNMP" on both PCs, made sure the service is running correctly and configured both services to accept SNMP queries from each other. I made sure to open up UDP port 161 in both PCs firewalls. Then I got the Net-SNMP binaries in order to use SNMPGET and SNMPWALK. As an alternative, I set up the SNMP extension for PHP through xampp (since I want to use PHP in my project once I get SNMP to work). Finally, I installed wireshark to monitor what exactly is going on and this is what I found:
When I try SNMPGET or SNMPWALK either through cmd or as a PHP command, I always get a timeout message. Wireshark is showing the get-next-request leaving one PC and arriving correctly on the other, so the network connection itself is working fine. But the receiving PC never sends a response. As I said, I'm pretty new to SNMP and I'm at a loss as to why this is happening. As I understand it, the optional feature for Windows 10 comes with its own SNMP agent, correct? If so, what could cause it to simply ignore an incoming request from a valid source IP?
The funny thing is that this even happens when I try to send an SNMP query to 127.0.0.1. I have no idea what I'm doing wrong...
Thanks to the comment of Lex Li, I was able to finally figure out which step I made a mistake with:
When setting up the SNMP service, under the security tab, I had to add 'public' as an accepted community name (with READ-ONLY rights). I figured since 'public' is sort of the standard read-only community, it would be accepted by default, which apparently it is not.
Alternatively, I guess I could have added my own communtiy name, but I didn't try that since I only want to read some values through SNMP anyways and read-only access is all I need for that.
Thank you very much Lex Li, I'm off to continue my project now!
About 5 days ago, OpenNMS Horizon 22.02 on Ubuntu 18.04.1 LTS stopped accepting traps from network elements. No changes were made to configuration or underlying operating system to my knowledge.
There are about 125 network elements, all Cisco, sending traps.
So far I have checked the following:
tcpdump shows the traps coming into the interface on port 162
Turned on Debug for trapd.log and incoming traps from network elements do not create any log entries
Traps sent with send-trap.pl from the localhost create traps that flow all the way to events
Traps sent with snmptrap either on localhost or another host create log entries that flow all the way to events. The other host is using the same interface that the network elements are using.
ss -lnpu sport = :162 shows an open UPD "UNCONN"
sudo lsof -i :162 shows a single listener java process
Startup of trapd does not seem to show any warnings in the log
I have verified that the ufw and iptables are off
I have updated OpenNMS to 22.04 and updated Ubunutu with no relief
Restarted OpenNMS many many times...
I moved Trapd startup after Asterisk in service-configuration.xml based on this
All of this seems similar to this. I think the last commenter on that thread asked about comparing the successful and unsuccessful traps in Wireshark which I have not done but all of the traps that are being sent have worked hundreds if not thousands of times until November 6th.
Is there anywhere else to look for errors as to why Trapd is not accepting traps? I think I have ruled out network issues.
I created a new Ubuntu 18.04 VM, updated it and then installed Horizon 23.01 fresh. I pointed my stream of traps at it and it behaves the exactly the same way, none of the traps create any log entries on the trapd.log with the level set to debug. Tcpdump shows the traps coming to the interface.
Issue Resolved.
The underlying operating system lost its static route for the subnet that the traps were coming from. OpenNMS had a route back to the subnet but not via the path that the traps were coming in from. Once the static route was restored, traps started working again and were flowing all the way to events.
ok so i have two machine on my LAN, one running Ubuntu 16.04 and the other Windows 10.
I installed and configured Freeswitch on the Linux one and installed X-Lite on the Windows one. What i'm trying to do is to register a SIP client using X-Lite on the Freeswitch server.
However each time i get the error message problem at server (SIP error 408)
The Wireshark entry on both machines gives this message
I configured the windows firewall to allow incoming connection on port 5060 and 5080 as freeswitch uses them, but still the same error!
can anyone help me?
Thanks
I am attempting to use RawCap to sniff Windows localhost. However, contrary to its billed ability to do so, it is not working. I am starting it as follows:
rawcap 127.0.0.1 echo.pcap
I then run a little echo TCP client / server test app I wrote. I use the client to send some data over 127.0.0.1, and it indeed gets printed on the server and sent back to the client, where it is also printed. Howver, the packet capture file is empty.
I am running under Windows XP, SP3.
Is anybody aware of any other steps I need to take to get this to work?
Additional information added on 7/20/2011: I contacted the company that produces RawCap, and they suggested making sure that I have administrator privilege, that I try sniffing ping 127.0.0.1, and that I try enabling telnet and sniffing telnet 127.0.0.1. I do indeed have administrator privilege, RawCap sees ping packets, but it did not see telnet packets. I also tried sniffing 127.0.0.1 on another machine, and I failed there also.
Best,
Dave
I've been in contact with the author of RawCap, and he indicated that I found a bug where Windows XP SP 3 can't sniff TCP on localhost. He does not seem hopeful that he can fix it. If any more useful information comes along, I will, in an attempt to help the community, comment on this answer.