Hi all.
Sorry for my english, it is not native for me.
I've three devices:
- C2801 (c2801-adventerprisek9-mz.124-3h);
- C2960 (c2960-lanbase-mz.122-35.SE5);
- Sun Fire X2100 M2 (FreeBSD 8.1-RELEASE amd64);
They are connected so:
c2801-fa0/1 <--> fa0/24-c2960-fa0/3 <--> bge0-Sun_Fire_X2100_M2 in vlan id 17 802.1q
bge0 is Broadcom BCM5715C 10/100/100 PCIe Ethernet Controller.
cisco 2801 is default router for FreeBSD in vlan17 & has ip XXX.YYY.254.33
MTU on FreeBSD interfaces:
System MTU and Fa0/3, Fa0/24 MTU on catalyst:
MTU on fa0/1.17 on c2801
Try to ping cisco 2801 from freebsd one whith df bit. IMHO maximum packed size should be 1500 - 20 (ip and tcp header) - 8 (icmp header) = 1472.
But I see:
Can anybody explain me - where is 200 bytes?
Has anybody some ideas how to fix this situation?
Sorry for my english, it is not native for me.
I've three devices:
- C2801 (c2801-adventerprisek9-mz.124-3h);
- C2960 (c2960-lanbase-mz.122-35.SE5);
- Sun Fire X2100 M2 (FreeBSD 8.1-RELEASE amd64);
They are connected so:
c2801-fa0/1 <--> fa0/24-c2960-fa0/3 <--> bge0-Sun_Fire_X2100_M2 in vlan id 17 802.1q
bge0 is Broadcom BCM5715C 10/100/100 PCIe Ethernet Controller.
cisco 2801 is default router for FreeBSD in vlan17 & has ip XXX.YYY.254.33
MTU on FreeBSD interfaces:
Code:
bge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=8009b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,LINKSTATE>
ether 00:1b:24:5d:38:1f
media: Ethernet 100baseTX <full-duplex>
status: active
[root@sf1 /usr/home/sudosu]# ifconfig vlan17
vlan17: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=3<RXCSUM,TXCSUM>
ether 00:1b:24:5d:38:1f
inet XXX.YYY.254.35 netmask 0xfffffff0 broadcast XXX.YYY.254.47
media: Ethernet 100baseTX <full-duplex>
status: active
vlan: 17 parent interface: bge0
[root@sf1 /usr/home/sudosu]#
Code:
C2960-24-SPB-SRV1#sh sys MTU
System MTU size is 1500 bytes
System Jumbo MTU size is 1500 bytes
Routing MTU size is 1500 bytes
C2960-24-SPB-SRV1#sh int fa0/3 mtu
Port Name MTU
Fa0/3 "sf1.tech bge0 tru 1500
C2960-24-SPB-SRV1#sh int fa0/24 mtu
Port Name MTU
Fa0/24 "Uplink 2800-SPB-S 1500
C2960-24-SPB-SRV1#
Code:
C2800-SPB-SRV#sh int fa0/1 | i MTU
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
C2800-SPB-SRV#sh int fa0/1.17 | i MTU
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
C2800-SPB-SRV#
But I see:
Code:
[root@sf1 /usr/home/sudosu]# ping -D -s 1273 -c 1 XXX.YYY.254.33
PING XXX.YYY.254.33 (XXX.YYY.254.33): 1273 data bytes
ping: sendto: Message too long
--- XXX.YYY.254.33 ping statistics ---
1 packets transmitted, 0 packets received, 100.0% packet loss
[root@sf1 /usr/home/sudosu]# ping -D -s 1272 -c 1 XXX.YYY.254.33
PING XXX.YYY.254.33 (XXX.YYY.254.33): 1272 data bytes
1280 bytes from XXX.YYY.254.33: icmp_seq=0 ttl=255 time=1.181 ms
--- XXX.YYY.254.33 ping statistics ---
1 packets transmitted, 1 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 1.181/1.181/1.181/0.000 ms
[root@sf1 /usr/home/sudosu]#
Can anybody explain me - where is 200 bytes?
Has anybody some ideas how to fix this situation?