diff --git a/Makefile b/Makefile
index aefaeed2..4ca453ed 100644
--- a/Makefile
+++ b/Makefile
@@ -110,7 +110,9 @@ $(OUT)/system/$(ITSCONFIG): build/$(EMULATOR)/$(ITSCONFIG)
 	cp=0; ca=0; \
 	$(TEST) $(CHAOS) != no && cp=1 && ca=$(CHAOS); \
 	x=`echo $(IP) | tr . ,`; \
+	g=`echo $(GW) | tr . ,`; \
 	$(SED) -e "s/%IP%/$$x/" \
+	    -e "s/%GW%/$$g/" \
 	    -e 's/%NETMASK%/$(NETMASK)/' \
 	    -e "s/%CHAOSP%/$$cp/" \
 	    -e "s/%CHAOSA%/$$ca/" < $< > $@
diff --git a/build/simh/config.202 b/build/simh/config.202
index 10b21820..829546af 100644
--- a/build/simh/config.202
+++ b/build/simh/config.202
@@ -830,6 +830,7 @@ DEFVKS			; Now uses standard virtual KS10 config
 DEFOPT IMPUS==236.	; IMP net host number (old-style) (206 octal)
 DEFOPT IMPUS3==<IPADDR 192,168,0,236>	; IP address
 DEFOPT NM%IMP==<IPADDR 255,255,255,0>	; Subnet mask
+DEFOPT GW%IMP==<IPADDR 139,185,5,1>	; Default gateway
 
 DEFINE ITSIRP BODY	; No local companions
 IRPS ITS,,[NX]
@@ -985,8 +986,10 @@ DEFSYM PMRCM==001777	;2.1 - 1.1 Physical page number
 			;	 addresses.) 
 DEFSYM PMUNSD==146000	;Unused bits
 
+;FIXME maybe US%ETH as per others below?
 DEFOPT ETHUS==<IPADDR %IP%>	; IP address
 DEFOPT NM%ETH==<IPADDR %NETMASK%>	; Subnet mask
+DEFOPT GW%ETH==<IPADDR %GW%>	; Default gateway
 DEFOPT PKTTRC==-1	;Packet tracing code enabled
 
 DEFINE ITSIRP BODY
diff --git a/src/system/ether.1 b/src/system/ether.1
index 28f1b8d8..8a055cea 100644
--- a/src/system/ether.1
+++ b/src/system/ether.1
@@ -237,7 +237,7 @@ ETHRX5:	POP P,H
 ;A contains datagram struct.
 ;Clobbers A, B.
 ;
-ETHTXI:
+IPKSNE:
 	PUSH P,C
 	PUSH P,D
 	PUSH P,E
diff --git a/src/system/inet.139 b/src/system/inet.139
index 9984d87e..98dcb054 100644
--- a/src/system/inet.139
+++ b/src/system/inet.139
@@ -1270,7 +1270,7 @@ IFN .-NIFIPN-NNIFS, .ERR Wrong size table - NIFIPN
 NIFIPO:	; IP Output routine for network interface
 	IFN IMPP, IPKSNA	; Send IP dgm to IMP output
 	IFN CHAOSP, IPKSNC	; Send IP dgm to Chaos, may fragment
-	IFN ETHERP, ETHTXI	; Send IP dgm to Ethernet, may fragment
+	IFN ETHERP, IPKSNE	; Send IP dgm to Ethernet, may fragment
 IFN .-NIFIPO-NNIFS, .ERR Wrong size table - NIFIPO
 
 ;NIFNAM: ; Interface name (in case of PEEKing someday?)
@@ -1309,10 +1309,7 @@ TERMIN
 	; Now define the prime & permanent gateways.
 	; Someday this really ought to be configurable either in CONFIG
 	; at assembly time, or from a file at runtime.
-IFE ITSMCH-SIXBIT/NX/,[
-	GWDEF 0,<HOSTN 139,185,5,1>,IPKSNA ; NPD cisco router, use for all.
-	NIPMGW==NIPPGW			; Number of prime gateways
-].ELSE [
+IFN 0,[					; Old MIT config disabled
 IFN IMPP,[
 IFE IPUNCP,[
 	GWDEF NW%LCS,<HOSTN 10,0,0,77>,IPKSNA 		; MIT-GW
@@ -1325,8 +1322,10 @@ IFN IPUNCP,[
 	GWDEF NW%AI, <HOSTN 128,31,6,2>,IPKSNC		; ???
 ] ;IFN IPUNCP
 ] ;IFN CHAOSP
+]
+IFDEF GW%IMP, GWDEF 0,GW%IMP,IPKSNA	; Default gateway via IMP
+IFDEF GW%ETH, GWDEF 0,GW%ETH,IPKSNE	; Default gateway via Ethernet
 	NIPMGW==NIPPGW			; Number of prime gateways
-] ; IF NOT NX
 
 BBLK