Sunsetsurf Techblog

Hyperterminal / command line modem calls

Not something you use much these days, but something I thought i’d note down here in case someone at some point needs it.

ATA (ata) Handshake sounds if modem speaker is enabled. Modem tries to answer call with handshake sounds. Press Enter to stop this process. The no carrier message is normal with this command. This command does not apply to Windows XP.

ATDT <ISP Phone Number>

For example, ATDT1234567 (where 1234567 is the connection number to dial for Internet service).

To connect to a test server in the US you can type:

ATDT18666633665 Login: _ Connects to a test server. If you can get to a login, your modem is working correctly.

ATDT (atdt) Dialtone if modem speaker is enabled. Indicates that the modem can get a dial tone. The message “no dial tone” indicates that either the modem or phone line is not working correctly. Press Enter to stop this process.

AT&F OK Resets most modems to factory defaults.

ATI0 (ati) 56000 ok The response varies between modems, but returns the modem speed..

ATI3 (ati) <Version and name> Returns the modem product type and firmware version.

ATZ (atz) ok This command resets the modem.

ATH (ath) ok Hangs up modem

ATS0=2 (ats0=2)

Zero, not the letter O . ok This command sets the modem to receive. Call the computer’s phone number and you should hear the handshake signal. Ring, ring displays on HyperTerminal screen, followed by no carrier , when the caller hangs up.

Checkpoint fw monitor to debug and trace traffic.

tcpdump is good, but for checkpoints to find out exactly what is happening to your traffic fw monitor is the way to go.

its usage is as follows to live debug traffic according to your filter:

# fw monitor -e “accept src=10.0.0.x;”

This will output in realtime the traffic going into your firewall from ip address 10.0.0.x

You will see output similar to the below:

Lan1:i[84]: 10.0.0.1 ->192.168.0.1 (ICMP) len=84 id=0 <———– This shows traffic coming into interface Lan1 but before rules have been processed thats the lowercase i.

ICMP: type=8 code=0 echo request id=64597 seq=5025

Lan1:I[84]: 10.0.0.1 -> 192.168.0.1 (ICMP) len=84 id=0 <——— This shows traffic still on interface Lan1 but after rules have been processed hence the uppercase I, if firewalls were dropping this packet you would not see this.

ICMP: type=8 code=0 echo request id=64597 seq=5025

Lan5:o[84]: 10.0.0.1 -> 192.168.0.1 (ICMP) len=84 id=0 <———-Now we see traffic going out of the destination interface Lan5 but again before the rules have been processed – lowercase o.

ICMP: type=8 code=0 echo request id=64597 seq=5025

Lan5:O[84]: 10.0.0.1 ->192.168.0.1 (ICMP) len=84 id=0 <———-Finally we see traffic going out of the destination interface Lan 5 after successfully traversing the rules – uppercase O

There is a load of filters you can apply, the example above uses src, but you can also use keywords such as dst, sport, dport etc..

Check this doc for a full list of what you can and can’t do..

http://www.checkpoint.com/techsupport/downloads/html/ethereal/fw_monitor_rev1_01.pdf

Checkpoint FW HA debugging.

Some useful commands to help you if you need to debug a possible problem with HA or clusterXL services.

# cphaprob stat

This command shows you the current status of your ha configuration – ideally you will see OK’s rather than problem, it will also tell you the which node is the primary.

# cphaprob -ia list

This give you a bit more detail on any problems and which if any daemons have failed. So for example, if your fwd daemon has failed you would see a state of problem.

# cphaprob -a if

This shows you the interfaces, whether they are up, and whether they are running multicast or broadcast – this should be the same on the secondary node.

#fw stat

Shows you the host and the currently installed policy along with a list of your interfaces in use.

# netstat -i

Regular linux command, but useful as it shows you the state of your interfaces, and whether there is a possible network problem.