SOL_AX25 undefined when compiling call.c

[Cathryn Mataga http://junglevision.com]

I'm running Redhat 6.0 and have downloaded the axutils 2.1.42 and 
call.c cannot compile, saying that it doesn't know about SOL_AX25.  Yet,
I can't find SOL_AX25 defined in any of the lib/*.h files.  It says
I'm running egcs-2.91.66.  I don't know what else I could have done
to break this.  The linux install is recent and pretty clean aside
from ax25 stuff.