Newer FreeBSD versions require (/32, /128) nmasks for aliases on public
interfaces. Warn, but do not quit if the explicit mask is too small.

Index: src/pgl/VerFourAsSym.cc
===================================================================
RCS file: /usr/local/CVS/polygraph/src/pgl/VerFourAsSym.cc,v
retrieving revision 1.5
diff -u -r1.5 VerFourAsSym.cc
--- src/pgl/VerFourAsSym.cc	9 Sep 2003 23:37:05 -0000	1.5
+++ src/pgl/VerFourAsSym.cc	17 May 2006 00:29:59 -0000
@@ -171,17 +171,24 @@
 int VerFourAsSym::addAddr(Array<PglNetAddrRange*> &ranges, const NetAddrSym &addr, int subnet) const {
 	NetAddrSym *clone = (NetAddrSym*)addr.clone();
 	int explicitSubnet = -1;
-	// note: newer FreeBSD versions may require (/32, /128) nmasks for aliases
 	if (!clone->subnet(explicitSubnet))
 		clone->setSubnet(subnet);
 	else
 	if (explicitSubnet <= subnet) // XXX: this logic is not IPv6-aware
 		subnet = explicitSubnet;
 	else {
-		cerr << addr.loc() << "error: the explicit subnet of the " << addr
-			<< " address (/" << explicitSubnet << ") is 'smaller' than"
-			<< " minimal subnet required to accomodate all agent addresses"
-			<< " on one host (/" << subnet << ")" << endl << xexit;
+		// Newer FreeBSD versions require (/32, /128) nmasks for aliases.
+		// Warn, but do not quit.
+		const int currentHash = explicitSubnet ^ subnet;
+		static int warnLessHash = ~currentHash; // initialized once
+		if (currentHash != warnLessHash) {
+			warnLessHash = currentHash;
+			clog << addr.loc() << "warning: the explicit subnet of the " << 
+				addr << " address (/" << explicitSubnet << ") is 'smaller' " <<
+				"than minimal subnet required to accomodate all agent " <<
+				"addresses on one host (/" << subnet << "). Whether this " <<
+				"is OK depends on your environment." << endl;
+		}
 	}
 
 	PglNetAddrRange r;