If you need to trace the HTTP request and response headers by capturing the related packets, you can use tcpdump in this way:
tcpdump -i ens192 -A -s 10240 'tcp port 80' | grep -v IP | egrep --line-buffered "..(GET |\.HTTP\/|POST |HEAD )|^[A-Za-z0-9-]+: " |sed -r 's/..(GET |HTTP\/|POST |HEAD )/\n\n\1/g'
For example, filtering tcp port 80 and 192.168.10.100 IP address:… Read more
I manage a 2 node VSX clusterXL environment that hosts 3 firewalls (virtual systems).
Some days ago I came across a problem in which one of them started (or maybe more time ago but not aware) to experience bad performance, outages, timeouts…
Trying to make a failover and move the VS to the other node fixed the problem until … Read more
“Database Revision Control” is a really useful feature when you are going to make important and/or many changes in the firewall policy, objects…
To make an analogy, DRC are like snapshots (as in the case of VMWare of a virtual machine) of the policies, objects, etc … everything that contains the database of the management server of Checkpoint is backed … Read more
Last week I came across a DHCP problem. Devices from certain VLAN were not getting DHCP assigned IP.
Even though firewall policy should have accepted those packets, tcpdump showed Checkpoint gateway was not forwarding them to the destination.
To capture DHCP traffic:
# tcpdump -n -i <interface> port 67 or port 68 -e
Incoming interface DHCP tcpdump:
… Read more
When connecting to checkpoint gateways, there may be a delay of 5 or more seconds when waiting for the password prompt. This is due a reverse DNS lookup that the gateway cannot perform until timeout is reached.
The UseDNS option of the SSH daemon can be disabled to avoid this behaviour:
Save a backup of the sshd_config file
… Read more
Due to some network infrastructure changes, the traffic passing through my internal FW (a Checkpoint VSX virtual system) started to suffer latency and packet loss.
No change had been made to the Checkpoint VSX, but for any reason, since that network changes, Checkpoint was not processing the traffic succesfully.
Performing a top on the VSX appliance containing the active “iNTERNAL … Read more
There are several reasons to force a failover on a firewall cluster (in this case a virtual system on a 2 node Checkpoint VSX cluster). For example, testing, analyzing or maintenance purposes.
First of all, we can check the cluster and virtual systems states by executing the command on the VS0 (on Gaia clish or expert mode):
… Read more