Pfsense 2.0.1 don't fragment packets bigger than interface MTU

[Alx1m1K]

Hello. I noticed, that on my pfsense 2.0.1 box packets bigger than interface MTU just discarded instead of getting fragmented.
For example: ping from one PC to another via switch works

PS C:\Users\AlximiK> ping 172.30.1.50 -l 64000

Обмен пакетами с 172.30.1.50 по с 64000 байтами данных:
Ответ от 172.30.1.50: число байт=64000 время=2мс TTL=64
Ответ от 172.30.1.50: число байт=64000 время=2мс TTL=64
Ответ от 172.30.1.50: число байт=64000 время=2мс TTL=64
Ответ от 172.30.1.50: число байт=64000 время=2мс TTL=64

Статистика Ping для 172.30.1.50:
    Пакетов: отправлено = 4, получено = 4, потеряно = 0
    (0% потерь)
Приблизительное время приема-передачи в мс:
    Минимальное = 2мсек, Максимальное = 2 мсек, Среднее = 2 мсек

but from and to pfsense box it is a problem:

PS C:\Users\AlximiK> ping 172.30.1.1 -l 2000

Обмен пакетами с 172.30.1.1 по с 2000 байтами данных:
Превышен интервал ожидания для запроса.
Превышен интервал ожидания для запроса.
Превышен интервал ожидания для запроса.
Превышен интервал ожидания для запроса.

Статистика Ping для 172.30.1.1:
    Пакетов: отправлено = 4, получено = 0, потеряно = 4
    (100% потерь)

and

[2.0.1-RELEASE][admin@midgard.home]/(33): ping -s 2000 172.30.1.50 
PING 172.30.1.50 (172.30.1.50): 2000 data bytes
^C
--- 172.30.1.50 ping statistics ---
8 packets transmitted, 0 packets received, 100.0% packet loss

Big incoming packets just counted as input errors

[2.0.1-RELEASE][admin@midgard.home]/(34): netstat -I sge0
Name               Mtu Network       Address              Ipkts Ierrs Idrop    Opkts Oerrs  Coll
sge0              1500 <link#1>      00:1b:fc:56:f5:45 132139701    77     0 162022955     0     0
sge0              1500 172.30.1.0    midgard             166601     -     -   136383     -     -
sge0              1500 fe80:1::21b:f fe80:1::21b:fcff:        0     -     -        0     -     -</link#1>

On both PCs MTU are 9K, on pfsense its 1500. How can I solve this problem? Please advise.

[cmb]

An incoming frame larger than the interface MTU is indeed an error. Up the MTU and it'll pass it if it can.

[Alx1m1K]

Ok, and what about outgoing frame, why this

[2.0.1-RELEASE][admin@midgard.home]/(33): ping -s 2000 172.30.1.50 
PING 172.30.1.50 (172.30.1.50): 2000 data bytes
^C
--- 172.30.1.50 ping statistics ---
8 packets transmitted, 0 packets received, 100.0% packet loss

is not working? Shouldn't pfsense fragment the packet before sending it (like windows does)? 172.30.1.50 is a freebsd9 pc with 9K mtu on interface and frames are properly fragmented before they sent out.

root@freebsd9-storage:/home/alximik# ping -S 172.30.1.50 -s 18000 172.30.1.20
PING 172.30.1.20 (172.30.1.20) from 172.30.1.50: 18000 data bytes
18008 bytes from 172.30.1.20: icmp_seq=0 ttl=128 time=1.270 ms
18008 bytes from 172.30.1.20: icmp_seq=1 ttl=128 time=1.318 ms
18008 bytes from 172.30.1.20: icmp_seq=2 ttl=128 time=1.248 ms
18008 bytes from 172.30.1.20: icmp_seq=3 ttl=128 time=1.309 ms
18008 bytes from 172.30.1.20: icmp_seq=4 ttl=128 time=1.237 ms
^C
--- 172.30.1.20 ping statistics ---
5 packets transmitted, 5 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 1.237/1.276/1.318/0.032 ms

============================
Checked the capture, the cause is big echo reply. It was pretty stupid. Please close this topic =)