gawk - Trouble with arrays of arrays to catch duplicate strings - multidimensional-array

Question

I am using gawk 4.1.1 to parse Cisco IOS configuration files, comparing switch configs to the routers above them, to eventually pull out IP addresses. My problem is I need to skip a record (interface) if I have already processed the vlan before. The catch is I am processing multiple files from different sites, and each site has it's own vlans.
So I thought an array of arrays would work best, where array[pop] could be array[den01], array[nyc01], etc. Dynamically creating those index-arrays from the variable pop, pulled from a text file.
The data processing works fine, except that it produces duplicate vlan numbers at a given site. The "dbfile" contains every vlan seen on every switch, from every site, and some people have redundant links so their vlan shows up twice.
Below is a snippet of my code:
#!/bin/bash
for i in `cat dbfile` ]; do
# set lots of variables to pull into awk
awk -v i=$i -v name=$name -v intname=$intname -v cvupfile=$cvupfile -v pop=$pop -v cid=$cid -v custvlan=$custvlan 'BEGIN { RS="!"; FS=" "; array[pop][0] = "" }
{
if ( $1 ~ "interface" && $2 ~ "Vlan" )
{
# trim Vlan ID so only the actual vlan number remains
seenvlan=gensub(/^Vlan/, "", "g", $2)
if ( seenvlan == custvlan )
{
# this is where trouble starts. I never get this IF to be true
if ( custvlan in array[pop] )
{
print "Duplicate VLAN found!"
}
else
{
# vlan is unique, make index for it
array[pop][custvlan]=custvlan
# debug output
for ( i in array )
print "This is first element: " i
for ( j in array[i] )
print "This is second element: " array[i][j]
print "Here is value from array: " array[pop][custvlan]
exit
}
}
}
}
END {
}' $crt
done
Here is some sample output. It shows 3 records processed. The fact that "This is the second element" is printed twice seems like a clue, but I'm not sure what it means. I am making a bunch of null indexes under array[pop]?
This is first element: den01
This is second element:
This is second element: 235
Here is value from array: 235
This is first element: den01
This is second element:
This is second element: 279
Here is value from array: 279
This is first element: den01
This is second element:
This is second element: 131
Here is value from array: 131