--- chan_iax2.c.orig	2006-01-09 23:48:48.000000000 +0100
+++ chan_iax2.c	2006-01-21 15:06:50.000000000 +0100
@@ -392,6 +392,7 @@
 
 struct iax2_registry {
 	struct sockaddr_in addr;		/*!< Who we connect to for registration purposes */
+	char hostname[80];
 	char username[80];
 	char secret[80];			/*!< Password or key name in []'s */
 	char random[80];
@@ -1036,6 +1037,26 @@
 	return res;
 }
 
+static void iax2_refresh_register_dns(struct iax2_registry *reg)
+{
+	struct ast_hostent ahp; 
+	struct hostent *hp;
+	char oldaddr[INET_ADDRSTRLEN];
+	char newaddr[INET_ADDRSTRLEN];
+	ast_log(LOG_DEBUG, "Refreshing DNS entry for '%s'\n", reg->hostname);
+	hp = ast_gethostbyname(reg->hostname, &ahp);
+	if (!hp) {
+	    ast_log(LOG_WARNING, "Host '%s' not found \n", reg->hostname);
+	} else {
+	    ast_inet_ntoa(oldaddr,sizeof(oldaddr),reg->addr.sin_addr);
+	    ast_inet_ntoa(newaddr,sizeof(newaddr),*((struct in_addr *)hp->h_addr));
+	    if (strcmp(oldaddr,newaddr)!=0) {
+		memcpy(&reg->addr.sin_addr, hp->h_addr, sizeof(&reg->addr.sin_addr));
+		ast_log(LOG_NOTICE, "Host '%s' changed IP addr from %s to %s\n", reg->hostname, oldaddr,newaddr);
+	    }
+	}
+}
+
 static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int lockpeer, int sockfd)
 {
 	int res = 0;
@@ -1730,6 +1751,8 @@
 								memset(&iaxs[f->callno]->reg->us, 0, sizeof(iaxs[f->callno]->reg->us));
 								iaxs[f->callno]->reg->regstate = REG_STATE_TIMEOUT;
 								iaxs[f->callno]->reg->refresh = IAX_DEFAULT_REG_EXPIRE;
+								/* the timeout could be because the remote server has changed his IP address. Make sure we got the right one */
+								iax2_refresh_register_dns(iaxs[f->callno]->reg);
 							}
 							iax2_destroy_nolock(f->callno);
 						}
@@ -4342,23 +4365,23 @@
 
 static int iax2_show_registry(int fd, int argc, char *argv[])
 {
-#define FORMAT2 "%-20.20s  %-10.10s  %-20.20s %8.8s  %s\n"
-#define FORMAT "%-20.20s  %-10.10s  %-20.20s %8d  %s\n"
+#define FORMAT2 "%-30.30s %-20.20s  %-10.10s  %-20.20s %8.8s  %s\n"
+#define FORMAT "%-30.30s %-20.20s  %-10.10s  %-20.20s %8d  %s\n"
 	struct iax2_registry *reg;
-	char host[80];
+	char ip[80];
 	char perceived[80];
 	char iabuf[INET_ADDRSTRLEN];
 	if (argc != 3)
 		return RESULT_SHOWUSAGE;
 	ast_mutex_lock(&peerl.lock);
-	ast_cli(fd, FORMAT2, "Host", "Username", "Perceived", "Refresh", "State");
+	ast_cli(fd, FORMAT2, "Host", "IP", "Username", "Perceived", "Refresh", "State");
 	for (reg = registrations;reg;reg = reg->next) {
-		snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(iabuf, sizeof(iabuf), reg->addr.sin_addr), ntohs(reg->addr.sin_port));
+		snprintf(ip, sizeof(ip), "%s:%d", ast_inet_ntoa(iabuf, sizeof(iabuf), reg->addr.sin_addr), ntohs(reg->addr.sin_port));
 		if (reg->us.sin_addr.s_addr) 
 			snprintf(perceived, sizeof(perceived), "%s:%d", ast_inet_ntoa(iabuf, sizeof(iabuf), reg->us.sin_addr), ntohs(reg->us.sin_port));
 		else
 			ast_copy_string(perceived, "<Unregistered>", sizeof(perceived));
-		ast_cli(fd, FORMAT, host, 
+		ast_cli(fd, FORMAT, reg->hostname, ip, 
 					reg->username, perceived, reg->refresh, regstate2str(reg->regstate));
 	}
 	ast_mutex_unlock(&peerl.lock);
@@ -5516,6 +5539,7 @@
 			ast_copy_string(reg->secret, secret, sizeof(reg->secret));
 		reg->expire = -1;
 		reg->refresh = IAX_DEFAULT_REG_EXPIRE;
+		ast_copy_string(reg->hostname,hostname,sizeof(reg->hostname));
 		reg->addr.sin_family = AF_INET;
 		memcpy(&reg->addr.sin_addr, hp->h_addr, sizeof(&reg->addr.sin_addr));
 		reg->addr.sin_port = porta ? htons(atoi(porta)) : htons(IAX_DEFAULT_PORTNO);
@@ -7397,6 +7421,8 @@
 						manager_event(EVENT_FLAG_SYSTEM, "Registry", "Channel: IAX2\r\nUsername: %s\r\nStatus: Rejected\r\nCause: %s\r\n", iaxs[fr.callno]->reg->username, ies.cause ? ies.cause : "<unknown>");
 					}
 					iaxs[fr.callno]->reg->regstate = REG_STATE_REJECTED;
+					/* MAYBE _our_ server just changed his IP and the old IP has been taken by another iax server, so make sure we have the right IP */
+					iax2_refresh_register_dns(iaxs[fr.callno]->reg);
 				}
 				/* Send ack immediately, before we destroy */
 				send_command_immediate(iaxs[fr.callno], AST_FRAME_IAX, IAX_COMMAND_ACK, fr.ts, NULL, 0,fr.iseqno);