FVS336Gv3 & FVS336Gv2: Is there a trick to getting CLI "show net lan dhcp logs" to show you the log?

I wanted to update this with some of the info that I have discovered.

First -- The telnet (CLI) interface command "show net lan dhcp logs" does occasionally return something. If there are any "local7.err" lines in the buffer when I run the command, they print out. This seems like a fairly straightforward bug in the CLI implementation, and I expect that it's not going to be fixed since this is a deprecated product.

Secondly -- I have written a script with curl commands that log into a router using the web interface and navigate to the DHCP page. Then the script uses grep to pick out the DHCP log lines, some perl one-liners to strip off the html, appends it to the previous DHCP log, and pipes it through sort and uniq to build a DHCP log over time. One of the things I like about the LAN Groups in the web interface is that it shows an * character next to the hosts that got their IP's via DHCP, so once I got the DHCP log scraper working it wasn't too much more work to scrape the LAN Groups data out, too. There I keep two files going -- one is LANgroups.curr.txt which has a snapshot at the time the scrape was run, while LANgroups.txt uses repeated apends followed by sort and uniq to get a cumulative listing of any hostname/IP/MAC triple that appeared over time. (I also discovered this way that the DHCP names evolve as hosts join a network. It's been an interesting learning experience!)

If anyone is interested in seeing the script, here it is:

#!/bin/bash

routerIP="$1"
filePath="$2"
username="$3"
password="$4"

echo $routerIP

mkdir -p $filePath
touch $filePath/dhcp.log
touch $filePath/LANgroups.txt

date
echo "$filePath starting up..."

curl -k "https://$routerIP/scgi-bin/platform.cgi" -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:61.0) Gecko/20100101 Firefox/61.0' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' -H 'Accept-Language: en-US,en;q=0.5' --compressed -H "Referer: https://$routerIP/scgi-bin/platform.cgi?page=index.htm" -H 'Content-Type: application/x-www-form-urlencoded' -H 'Connection: keep-alive' -H 'Upgrade-Insecure-Requests: 1' --data "thispage=index.htm&USERDBUsers.UserName=$username&USERDBUsers.Password=$password&USERDBDomains.Domainname=geardomain&button.login.USERDBUsers.router_status=Login&Login.userAgent=Mozilla%2F5.0+%28Macintosh%3B+Intel+Mac+OS+X+10.13%3B+rv%3A61.0%29+Gecko%2F20100101+Firefox%2F61.0" -c $filePath/cookieJar > $filePath/addresses.html

curl -k "https://$routerIP/scgi-bin/platform.cgi?page=dhcp_logs.htm" -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:61.0) Gecko/20100101 Firefox/61.0' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' -H 'Accept-Language: en-US,en;q=0.5' --compressed -H "Referer: https://$routerIP/scgi-bin/platform.cgi?page=lan_setup.htm" -H 'Connection: keep-alive' -H 'Upgrade-Insecure-Requests: 1' -b $filePath/cookieJar  > $filePath/dhcp.html

curl -k "https://$routerIP/scgi-bin/platform.cgi?page=lan_groups.htm" -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:61.0) Gecko/20100101 Firefox/61.0' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' -H 'Accept-Language: en-US,en;q=0.5' --compressed -H "Referer: https://$routerIP/scgi-bin/platform.cgi?page=dhcp_logs.htm" -H 'Connection: keep-alive' -H 'Upgrade-Insecure-Requests: 1' -b $filePath/cookieJar  > $filePath/LANgroups.html

curl -k "https://$routerIP/scgi-bin/platform.cgi?page=index.htm" -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:61.0) Gecko/20100101 Firefox/61.0' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' -H 'Accept-Language: en-US,en;q=0.5' --compressed -H "Referer: https://$routerIP/scgi-bin/js/lanGroups.js" -H 'Connection: keep-alive' -H 'Upgrade-Insecure-Requests: 1' -b $filePath/cookieJar > /dev/null

grep " \[DHCPD\]" $filePath/dhcp.html > $filePath/dhcp.txt
perl -p -i -e 's/^[^>]*>//g' $filePath/dhcp.txt
cat $filePath/dhcp.txt | grep "DHCPACK on " | grep "(" > $filePath/dhcp.int.txt
cat $filePath/dhcp.log $filePath/dhcp.int.txt > $filePath/dhcp.new
cat $filePath/dhcp.new | sort -k1M -k2 -k3 | uniq > $filePath/dhcp.log

grep "tb2New" $filePath/LANgroups.html > $filePath/LANgroups.int.txt
perl -p0 -i -e 's/\t\t\t\t\t\t\t\t\<td class\=\"tb2New w12\"\>\n\t\t\t\t\t\t\t\t\t<td class="tb2New">//g' $filePath/LANgroups.int.txt
perl -p0 -i -e 's/\<\/td\>\n\t\t\t\t\t\t\t\t\t\<td class\=\"tb2New\"\>/\t/g' $filePath/LANgroups.int.txt
perl -p0 -i -e 's/\tGROUP1\tDefault\<\/td\>\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\<td class\=\"tb2New\"\>//g' $filePath/LANgroups.int.txt
cat $filePath/LANgroups.int.txt  | sort -n -t . -k1,1 -k2,2 -k 3,3 -k4,4  > $filePath/LANgroups.curr.txt
cat $filePath/LANgroups.int.txt $filePath/LANgroups.txt > $filePath/LANgroups.new
cat $filePath/LANgroups.new  | sort -n -t . -k1,1 -k2,2 -k 3,3 -k4,4 | uniq > $filePath/LANgroups.txt

date
echo "$filePath ...done"

(Note that I strip out what I consider uninteresting DHCP traffic with the line

cat $filePath/dhcp.txt | grep "DHCPACK on " | grep "(" > $filePath/dhcp.int.txt

I'm only interested in lines that associate MAC addresses with DHCP names. If you want the entire log file, just skip that line and in the next line you would append $filePath/dhcp.txt rather than $filePath/dhcp.int.txt to make $filePath/dhcp.new)

(I use lots of intermediate files because it's easier to debug -- you can adapt this so that it doesn't spew files quite so badly.)