Configuration Example, Firewalling

Cisco ASA – Reset TCP connection

René Jorissen on August 22, 2011 2 Comments • Tags: #application #asa #cisco #idle #legacy #packet #psh #reset #rset #tcp #timeout

“Normal” TCP applications use a three-way handshake to establish a session. After data has been send the session is closed. Some legacy applications don’t always close a TCP session. They keep the session open, even when the session is idle for a long time (+ 2 hours). When the session is idle and a client … Read More

Firewalling, IPSec / SSL VPN

Microsoft Outlook through Citrix Access Gateway SSL IP VPN

René Jorissen on October 31, 2008 1 Comment • Tags: #135 #1536 #access #administrator #ampr #amprinter #cag #citrix #epmap #exchange #gateway #inter #ip #microsoft #outlook #ssl #tcp #vpn

One of our customers wants you use their locally installed Microsoft Outlook through a Citrix Access Gateway (CAG). Sales people from that customer travel through the country and use the Outlook offline to read or prepare e-mail to send later. These people use UMTS technology to connect their laptops to the Internet. The customers wants … Read More

Configuration Example

Telnet Time-Out is killing me….

René Jorissen on October 22, 2008 0 Comments • Tags: #connection #ip #out #synwait #synwaittime #tcp #telnet #time #timed

Aaarrrgggghhh, I hate it when I would like to telnet into a device and enter the wrong IP address. This means, by default, waiting for 30 seconds before being able to correct the IP address and start a new telnet session, because there is no escape sequence. SW01#telnet 10.100.12.250 Trying 10.100.12.250 … % Connection timed out; … Read More

Configuration Example, IP Telephony

QoS matching for VoIP

René Jorissen on April 18, 2008 0 Comments • Tags: #1720 #2427 #2428 #h225 #h245 #h323 #mgcp #payload #rtcp #rtp #sccp #sgcp #signaling #tcp #udp #voip

Voice over IP is, as you know for sure, very time-sensitive traffic. That is why VoIP signaling and payload traffic should receive enough bandwidth and as less jitter and delay as possible. QoS is an important tool to assign VoIP traffic more preference over “normal” traffic. Important for QoS tools to function correctly is placing … Read More