16 million failed SIP registrations in 24 hours from 1 host
I recently stood up a Bicom PBXware virtual machine to do some testing. I noticed that there were a few thousand SIP registration failures a couple hours later…
Category
Networking
38 articles in this category
Detecting if SIP ALG is enabled on network
One of the first things I troubleshoot in a SIP trouble ticket is determining if the network is SIP aware. Sometimes I don’t have access to the network…
Unable to negotiate with port 22: no matching key exchange method found.
Working with an older Cisco ASA, I was not able to directly SSH to the host using SSH on Windows unless I specified the diffie-hellman-group1-sha1 algorithm. PuTTY gives…
Could not establish trust relationship for the SSL/TLS secure channel.
Working with some older Cisco ASA devices, I’m trying to access the ASDM interface. The browser isn’t giving me luck, so I turned to PowerShell to help me,…
Cisco WAP571 SNMP poll of apRadioNumAssociatedStations returning 0
For some reason on a Cisco WAP571, the SNMP value returned from apRadioNumAssociatedStations is always zero. This is true on firmware tested WAP571 (pgwap571, 1.1.0.3). I have a…
snmptable
snmptable -Cl -CB -Ci -OX -Cb -Cc 16 -Cw 64 -v2c -c <community> <host:port> CISCO-WLAN-ACCESS-POINT-MIB::apAssocTable On a Cisco WAP571, it produces the following output. Interface Authenticated Associated RxPackets…
ISAKMP (IKE Phase 1) Status Messages MM_WAIT_MSG#
I've been meaning to copy this back here but haven't had the chance until now. I reference this so much, figured it'd have stuck in my mind by…
Warning, DHCP pool range is limited to 128 addresses
For all ASA models, the maximum number of DHCP client addresses varies depending on the license: If the limit is 10 hosts, the maximum available DHCP pool is…
The vpn client agent was unable to create the interprocess communication depot.
When installing Cisco AnyConnect VPN client, encountered an error: The vpn client agent was unable to create the interprocess communication depot. This error is due to Internet Connection…
Configure WPA on Cisco Aironet 350 Access Point
Quick setup for WPA on Cisco Aironet 350 Access Point to remind myself… interface Dot11Radio0 no ip address no ip route-cache ! encryption mode ciphers tkip ! ssid…
Enable SSH Login on a Cisco Router
Quick example of setting up SSH access on a Cisco router. I have a few dozen routers in my lab I'm working on and actually made this scripted.…
Configure Cisco ASA to Capture Specific Port Traffic
On a Cisco ASA you can configure capturing of data to allow for deeper troubleshooting of issues. With the recent issue of the Heartbleed bug, I needed a…
Test Cisco ASA VPN Authentication
Had an issue with a user that was failing to log into the VPN from remote. Couldn't initially figure it out while at home while troubleshooting the authentication. …
Cisco IOS EEM: Send Email on VPN Connection
I set up a Cisco router to send an email whenever a VPN user connected. I did this for accounting purposes before I moved to RADIUS. I'll put…
Cisco EEM Applet – Send Email Notification on Internet Circuit Failure
I needed to setup notification to be sent via email when a circuit went down and failed over to a backup circuit on a Cisco Router 2921. Here's…