Cisco ASA – Using ‘logging’ to see what ports are being blocked
KB ID 0000702 Problem If you look after a firewall, sooner or later something will fail, and the blame (rightly or wrongly), will be leveled at the firewall. I came back from holiday this week to find a client had got a problem with secure POP email. The problem had been fixed (temporarily) by dropping the affected users into a group, and opening all ports. As this had fixed the problem then it’s fair to say that the ASA was...
Cisco ASA to Juniper SRX Site to Site VPN
KB ID 0000710 Problem You want to establish a site to site VPN from a site with a Cisco ASA firewall, to another site running a Juniper SRX firewall. I had to do this this week, and struggled to find any good information to help. In the example below I’m configuring the whole thing from a laptop (172.16.254.206) that’s on the Juniper’s site. Use the diagram below, and substitute your own IP addresses and subnet...
Cisco ASA 5500 Allowing Tracert
KB ID 0000753 Problem I’d always assumed that as Tracert uses ICMP, and that simply adding ICMP inspection on the ASA would let Tracert commands work. A client of mine is having some comms problems and wanted to test comms from his remote DR site, he had enabled time-exceeded and unreachable on the ASA (for inbound traffic) and that had worked. I checked the default inspection map and found inspect ICMP was there? As it turns...
ASA TFTP Error – (Cannot allocate memory)
KB ID 0000787 Problem I updated my ASA to version 9.1(1) tonight, that went well, but when I tried to update the ASDM image to version 7.1(1)-52 this happened; Accessing tftp://10.254.254.109/asdm-711-52.bin…!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!...
Cisco ASA5500 Change the AnyConnect Port
KB ID 0000422 Problem AnyConnect runs over TCP port 443 (That’s HTTPS/SSL), but if you only have one public IP and need to forward that port to a web server or internal host then you are a bit snookered. You can of course change the port that AnyConnect runs over, so that it’s no longer on TCP port 443. Why you would NOT want to do this. Bear in mind that https is a well known port, and its open in most places for secure...