--- quagga-0.99.9-old/bgpd/bgp_network.h	2007-12-27 18:00:14.000000000 +0100
+++ quagga-0.99.9/bgpd/bgp_network.h	2007-12-27 18:06:06.131228697 +0100
@@ -25,6 +25,8 @@
 /* setsockopt Number */
 #define TCP_MD5SIG		14
 
+#ifndef TCP_MD5SIG_MAXKEYLEN /* some headers define struct tcp_md5sig */
+
 #define TCP_MD5SIG_MAXKEYLEN	80
 
 struct tcp_md5sig {
@@ -34,6 +36,8 @@
         __u32   __tcpm_pad2;                            /* zero */
         __u8    tcpm_key[TCP_MD5SIG_MAXKEYLEN];         /* key (binary) */
 };
+
+#endif /* defined(TCP_MD5SIG_MAXKEYLEN) */
 #endif /* defined(HAVE_TCP_MD5) && defined(GNU_LINUX) */
 
 #ifdef HAVE_TCP_MD5