Hi, The attached patch changes the type of "i" in ospf_hello_rx() from "u8" to "u32" to prevent bird from entering an endless loop here: for(i=0;i<size-(sizeof(struct ospf_hello_packet));i++) The problem occurs when: size-(sizeof(struct ospf_hello_packet)) > 255, which is the case when you start to have a lot of neighbors in the area (I triggered this while trying to run bird in an area with more than 60 neighbors). Regards, Rani --- bird-1.0.7/proto/ospf/hello.c 2003-08-14 10:13:14.000000000 +0200 +++ bird-1.0.7-debian/proto/ospf/hello.c 2003-09-03 05:57:13.000000000 +0200 @@ -59,7 +59,8 @@ { u32 nrid, *pnrid; struct ospf_neighbor *neigh,*n; - u8 i,twoway,oldpriority; + u32 i; + u8 twoway,oldpriority; ip_addr olddr,oldbdr; ip_addr mask; char *beg=": Bad OSPF hello packet from ", *rec=" received: ";