I successfully reproduced this on few different 4.8 routers. Does anybody knows what is this? How to fix or workaround this problem?
Alexander Motin wrote:
I have one strange problem with dummynet & IP fragmentation.
I have FreeBSD 4.8-RELEASE router with few interfaces: em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 options=3<rxcsum,txcsum> inet 195.248.191.172 netmask 0xffffffc0 broadcast 195.248.191.191 ether 00:30:48:20:8e:7e media: Ethernet autoselect (1000baseTX <full-duplex>) status: active ng4: flags=88d1<UP,POINTOPOINT,RUNNING,NOARP,SIMPLEX,MULTICAST> mtu 1492 inet 195.248.191.172 --> 212.86.231.58 netmask 0xffffffff
Interface ng4 have MTU 1492 because it is PPPoE link. When I do not use dummynet on router and somebody send a big (>1492bytes) packet to 212.86.231.58 with DontFragment flag set router generates ICMP reply message (Fragmentation Needed). This is correct.
But when I use dummynet on that interface: 10170 pipe 10009 ip from any to any out xmit ng4 10175 allow ip from any to any via ng4
10009: 128.000 Kbit/s 0 ms 50 sl. 1 queues (1 buckets) droptail mask: 0x00 0x00000000/0x0000 -> 0x00000000/0x0000 BKT Prot ___Source IP/port____ ____Dest. IP/port____ Tot_pkt/bytes Pkt/Byte Drp 0 udp 195.248.191.65/53 212.86.231.58/1118 50965 28380582 0 0 143
router stops sending that ICMP messages. Pipe is not overflowed at that tme, it is empty.
-- Alexander Motin _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "[EMAIL PROTECTED]"
