0
votes
0answers
9 views

SSH working, but SCP+git not working at all when network link is overloaded

SCP (and other programs that use SSH, like git) establishes a connection, but just sits there without doing anything. Using an SSH shell works fine. This only happens when the Ethernet network link ...
0
votes
1answer
64 views

Throughput decreases after MTU 5000

I am trying to test throughput between two computers directly connected through 1 GbE and testing with iperf. I am getting a throughput around 980Mbps when MTU is between 5000 and 5050, however it ...
1
vote
1answer
70 views

Drop IP fragments of a certain protocol

When conntrack is active, the iptables stack never sees a fragmented IP packet, only the reassembled one (source), so the -f test never matches. If I want to block any fragment I could set ...
3
votes
1answer
1k views

Windows 7 doesn't request MTU from DHCP server; what is it thinking?

My computer's Ethernet adapter uses 1,500 byte Ethernet frames. Normally this means that my Local Area Connection's MTU is 1500 bytes. But my (IPv4) connection to the Internet has some overhead. This ...
1
vote
2answers
169 views

Configure HP iLO MTU Setting - Site is behind several firewalls and MTU requires lowering for access

Just wondering if anyone knows how to adjust the MTU setting for a HP server iLO NIC? The site is behind several firewalls and we have had problems with other things that has required us to lower the ...
0
votes
0answers
174 views

Why does postfix take so long time to receive emails from gmail?

How can I manually check for an email from the command line? How can I force postfix to receive/update emails? The email from gmail takes 8 minutes till it will be received by postfix. How can I ...
0
votes
0answers
49 views

What is the relation between interface MTU and received packets length?

Let's say that two hosts A and B communicate via an Ethernet medium. Host A has MTU 1500 and host B has MTU 1300. If A is sending a packet with length 1500, will host B receive it?
0
votes
2answers
873 views

Timeout while testing MTU via ping

I tested it on Windows 7 and Ubuntu 11.10 with MTU size 1500B. IP packet - 20B ICMP packet - 8B 1500 - 28 = 1472 So maximum packet that I could ping without fragmentation is 1472B, and this is ...
2
votes
3answers
4k views

About MTU settings in machines and switch

Update: to be more realistic: M1 Switch and M2 are all running on a 10G network, and we use ipv4. The settings are: M1 has MTU set to 1500 Switch has MTU set to 9000 M2 has MTU set to 9000 Does ...
0
votes
2answers
2k views

Macbook Pro 2010 Ethernet Jumbo Frame(9k MTU) Support?

Has anyone been able to use jumbo frame support on their 2010 Macbook Pros? This is kind of negative news here, but I am seeing many reports that this is not available anymore due to Apple's choice ...
6
votes
5answers
6k views

Why does Mac OS X insist on changing my MTU to 1500?

Recently (I think after updating to 10.6.4) Mac OS X has insisted on changing my MTU to 1500, even though the router which my Mac connects to directly has an MTU of 1472. I've noticed that manually ...
9
votes
5answers
52k views

How to tell what MTU is being used in Windows XP

I'm suffering from a really weird problem where I randomly get "The connection to the server was reset" errors when trying to access web pages (HTTP error 12031 according to the Windows network ...