pcap_agent.tcl is the sguil component that handles, among other things, the 
pcap detail extraction launched in wireshark from the sguil.tk console.  By 
default, pcap_agent.tcl can be configured to support interfaces with either 
straight IP or VLANs using the "set VLAN" parameter in pcap_agent.conf.

We can support both use cases and links running mixed ip/vlan traffic by 
modifying pcap_agent.tcl with:

   set tcpdumpFilter "(ip and $tmpTcpdumpFilter) or (vlan and $tmpTcpdumpFilter)"

just after the if loop and not using the "set vlan" tag in pcal_agent.conf.