Use different loopback addresses for test switch

p2p/test_util.go

@@ -1,7 +1,9 @@
 package p2p
 
 import (
+	"fmt"
 	"net"
+	"sync/atomic"
 
 	crypto "github.com/tendermint/go-crypto"
 	cmn "github.com/tendermint/tmlibs/common"
@@ -130,6 +132,8 @@ func StartSwitches(switches []*Switch) error {
 	return nil
 }
 
+var listenAddrSuffix uint32 = 1
+
 func MakeSwitch(cfg *cfg.P2PConfig, i int, network, version string, initSwitch func(int, *Switch) *Switch) *Switch {
 	// new switch, add reactors
 	// TODO: let the config be passed in?
@@ -144,7 +148,7 @@ func MakeSwitch(cfg *cfg.P2PConfig, i int, network, version string, initSwitch f
 		Moniker:    cmn.Fmt("switch%d", i),
 		Network:    network,
 		Version:    version,
-		ListenAddr: cmn.Fmt("%v:%v", network, cmn.RandIntn(64512)+1023),
+		ListenAddr: fmt.Sprintf("127.0.0.%d:%d", atomic.AddUint32(&listenAddrSuffix, 1), cmn.RandIntn(64512)+1023),
 	}
 	for ch := range sw.reactorsByCh {
 		ni.Channels = append(ni.Channels, ch)