mtu help,weird size

roberto2212 · Post by **roberto2212** » Thu Dec 29, 2016 5:39 am

1.I set on billion 8800nl MTU 1492
2.I set on my computer MTU 1492
3.I tested my connection on website speedguide.net, tcp/ip analyzer
4.on tcp/ip analyzer showed me MTU = 1460
MTU is not fully optimized for broadband. Consider increasing your MTU to 1500 for better throughput. If you are using a router, it could be limiting your MTU regardless of Registry settings.
So I ask you why is my mtu 1460 if on router I set 1492 and pc same 1492?
When I play online gaming still I got delay 1 second.I think that is problem with MTU.
Can any one please help me?Thanks
« SpeedGuide.net TCP Analyzer Results »
Tested on: 2016.12.29 05:27
IP address: 91.135.x.xx
Client OS/browser: Windows 8.1 (Firefox 50.0)

TCP options string: 0204058c0103030801010402
MSS: 1420
MTU: 1460
TCP Window: 66560 (NOT multiple of MSS)
RWIN Scaling: 8 bits (2^8=256)
Unscaled RWIN : 260
Recommended RWINs: 65320, 130640, 261280, 522560, 1045120
BDP limit (200ms): 2662kbps (333KBytes/s)
BDP limit (500ms): 1065kbps (133KBytes/s)
MTU Discovery: ON
TTL: 115
Timestamps: OFF
SACKs: ON
IP ToS: 00000000 (0)

roberto2212 · Post by **roberto2212** » Fri Dec 30, 2016 9:37 am

auto mtu is off:
C:\Windows\system32>netsh interface tcp show gl
Querying active state...

TCP Global Parameters
----------------------------------------------
Receive-Side Scaling State : enabled
Chimney Offload State : disabled
NetDMA State : disabled
Direct Cache Access (DCA) : disabled
Receive Window Auto-Tuning Level : disabled
Add-On Congestion Control Provider : none
ECN Capability : disabled
RFC 1323 Timestamps : disabled
Initial RTO : 2000
Receive Segment Coalescing State : disabled
Non Sack Rtt Resiliency : disabled
Max SYN Retransmissions : 2

I made few test like:
1.set billion 8800nl to bridge mode + pc with pppoe connection mtu 1492..result on SG TCP/IP Analyzer mtu-1460
2.tryed different modem hg612 on bridge connection + pc with pppoe connection mtu 1492..result on SG TCP/IP Analyzer mtu-1460
3.set hg612 in bridge connection + linksys wrt 1900acs router with wan setup on pppoe + mtu 1492...result on SG TCP/IP Analyzer mtu-1460
4.all my network adapters was set mtu 1492
5.what is weird is that if I set on router mtu say 1451,1452,1453,1454 to max. 1460..then I checked on speedguide.net tcp/ip analyzer mtu..showed me correct mtu..mean if router 1452 then on speedguide same 1452
6.but if I set on router 1461 then on speedguide is 1460 max.
7.looks like I cant set up mtu more like 1460

Post by **Philip** » Sat Dec 31, 2016 9:49 am

Your MTU is likely being limited to 1460 by your ISP. It is not a huge issue, I wouldn't worry about it much.

roberto2212 · Post by **roberto2212** » Sat Dec 31, 2016 9:56 am

It is big issue because online gaming on ps4 laging and I got delay.Tested with my friend different location with different provider and no lag or delay on the end.My isp is idnet uk.My friend isp is sky with sky hub default mtu 1500.On speedguide showed me correct mtu 1500 like in router.Online gaaming like fifa or nhl 17 working perfect.So problem is mtu on my side.

Post by **Philip** » Sat Dec 31, 2016 10:32 am

I would do a couple of traceroutes to the destination game server and check where the ping spikes occur, it could be a routing/ISP issue that is not necessarily the MTU setting's fault.

roberto2212 · Post by **roberto2212** » Sat Dec 31, 2016 1:00 pm

Well, I did traceroute to game servers and sended to EA company.They said that everything is ok that must be problem local.Also I made traceroute on sky is well and is same like my isp idnet.What is weired is if I set billion 8800nl to bridge mode then connected to linksys wrt 1900acs with wan pppoe setup and mtu set auto then I set my pc default network adapter 1500, then rebooting pc,modem,router.I checked optimal mtu on pc first with Tcp optimizer mtu/latency and showed me you can set your mtu to 1492.Same result with cmd 1464 pass and 1465 need fragmented.1464+28=1492.Checked again on speedguide tcp/ip and showed me mtu=1460.Question is why my pc showed me 1492 optimal mtu if my isp limited mtu to 1460,router is auto and network adapter is 1500.Also tryed with manual mtu on router size 1460.This is really strange.