Questions tagged [mtu]
For questions about or in relation to the maximum transmission unit (MTU).
128
questions
3
votes
1
answer
359
views
MTU and MSS concept
A client and a server are separated by a router.
I don't understand the principle of MSS adjustment.
When the client sends a SYN packet to the server, the SYN/ack server replies with its MSS.
Example: ...
- 31
1
vote
1
answer
32
views
MTU - proactively setting to lower than 1500 on endpoints to prevent tunnel issues
With machines being deployed to various locations where internet is controlled by others, sometimes there can be one or two tunnels which necessitates using lower MTU to avoid communication issues, ...
- 133
5
votes
2
answers
781
views
Why is MSS important? Why can't we just rely on the MTU?
Note: I understand both what MTU and MSS do so I am not asking about their function here. I understand that when a TCP connection is being established, the MSS is exchanged and it dictates the maximum ...
- 877
1
vote
1
answer
54
views
Pinging packets greater than 1500 between two proper configured machines on proper configured networks, always possible?
Given the following 3 subnet topology, I will give names to them to simplify it, I am using planets, I see it as a perfect geographic enumeration.
Sites
Office on Earth 172.1.x FiOS, default MTU
...
- 113
1
vote
2
answers
1k
views
Is it safe to enable jumbo frames on switches in general
Can any harm occur by simply enabling jumbo frames on your switch infrastructure?
I understand that in a given flow from one machine to another all participants need to support jumbo frames to arrive ...
- 163
0
votes
1
answer
88
views
IP fragmentation and PMTUD
I have 2 questions.
1) According to a lot of sources, when IP packets gets fragmented, in this case, lets take icmp, the icmp header is present only in the first packet.
But I have observed on some ...
- 405
0
votes
1
answer
57
views
Why MTU setting change not showing any meaning change in file transfer via tcp?
I performed a test in which I transferred a file of 1GB by opening a tcp port on destination server with MTU 1000.
then I tried to change the MTU from 1000 to 9000 and the total time duration of 1GB ...
2
votes
2
answers
273
views
How can a router know the MTU of the next router?
https://www.cloudflare.com/learning/network-layer/what-is-mtu/
Suppose Server A and Computer A are connected, but the data packets
they send to each other have to pass through Router B and Router C
...
- 23
1
vote
2
answers
594
views
Brocade 7450 - set MTU to 9000
I have brocade icx 7450.
I already enabled jumbo frames to increase MTU packets on switch.
But unfortunately I am not able to change MTU size of port which I want. When typing after choosing interface ...
- 13
0
votes
2
answers
173
views
Sanity Check: Changing MTU on Wifi Endpoints (computers) should be a LAST resort, right?
A client of mine has an organizational network that is comprised of a lot of Ubiquity gear, primarily switches and wireless routers to power their network, with a Sophos XG firewall at the border.
...
- 181
0
votes
2
answers
968
views
GRE tunnel bridging and MTU mismatch
Background
My workplace has 2 office areas which is only 200 meters away from each other. They have their own local networks, their own Internet connections, with routers configured to fallback to the ...
- 433
5
votes
2
answers
754
views
Can a jumbogram (giant data packet) be used at a large scale (in WAN for example)?
There are many scientific paper for Jumbo frame, even more, some real implementations and deployments. But it is not the case for Jumbogram !!
Jumbo frame (geant frame) for Layer 2; Jumbogram (geant ...
- 63
2
votes
1
answer
742
views
What's the difference between MTU and MRU ? How come people talk so often about MTU and little consideration is given to MRU?
I don't understand why MRU isn't mentioned as frequently as its counterpart MTU. Are they always arranged to have the same value on a device ? A few days ago I noticed that my Windows machine accepted ...
- 41
2
votes
1
answer
2k
views
MTU mismatch scenario, two hosts handle in a different way ingoing packets bigger than local interface MTU. How does MTU really work?
I’ve been struggling with the MTU topic for a while and I still can’t get how it really works. The majority of books that I read and the courses that I attended all seem to treat this subject in a ...
- 41
0
votes
2
answers
2k
views
Does MTU setting affect sending, receiving, or both?
Consider the two devices:
A: PC, NIC MTU is set to 1500
B: Router, MTU of relevant interface is 1478
Now if A sends a frame of length 1500 to B, something might go wrong. But what if I set A 's MTU to ...
- 103