Hello, Example config file that causes the SEGFAULT: router id 192.168.1.1; protocol kernel { merge paths; ipv6 { export all; }; } Program terminated with signal SIGSEGV, Segmentation fault. #0 0x000056445cef23ea in krt_set_merge_paths (cc=0x0, merge=1, limit=16) at obj/conf/cf-parse.y:819 819 cc->ra_mode = merge ? RA_MERGED : RA_OPTIMAL; (gdb) bt #0 0x000056445cef23ea in krt_set_merge_paths (cc=0x0, merge=1, limit=16) at obj/conf/cf-parse.y:819 #1 0x000056445cefe0d5 in cf_parse () at obj/conf/cf-parse.y:4391 #2 0x000056445cf02d1c in config_parse (c=0x56445ec8b3f0) at conf/conf.c:140 #3 0x000056445cf93b8e in unix_read_config (cp=0x7ffe249d0930, name=0x56445cfb02d4 "bird.conf") at sysdep/unix/main.c:203 #4 0x000056445cf93bd5 in read_config () at sysdep/unix/main.c:213 #5 0x000056445cf94f21 in main (argc=1, argv=0x7ffe249d0a68) at sysdep/unix/main.c:855 (gdb) list 814 krt_set_merge_paths(struct channel_config *cc, uint merge, uint limit) 815 { 816 if ((limit <= 0) || (limit > 255)) 817 cf_error("Merge paths limit must be in range 1-255"); 818 819 cc->ra_mode = merge ? RA_MERGED : RA_OPTIMAL; 820 cc->merge_limit = limit; 821 } 822 823 static void (gdb) Kernel version: Linux edge 4.14.13-1-ARCH #1 SMP PREEMPT Wed Jan 10 11:14:50 UTC 2018 x86_64 GNU/Linux I am able to provide core dump and binary if necessary. Cheers, P.