Thank goodness there was MikroTik router on the client end of the link. MikroTik (and Linux) have a feature called “Clamp to pmtu” in mangle. This feature dynamically changes the MTU settings to match the smallest MTU from point to point and thereby prevents fragmentation and the weirdness I previously described. Here is my fix:
Full frame MTU. Full frame MTU indicates the actual size of the frame that is sent by a particular interface. Frame Checksum is not included as it is removed by an ethernet driver as soon as it reaches its destination. MAC/Layer-2/L2 MTU. L2MTU indicates the maximum size of the frame without the MAC header that can be sent by this interface. So also on systems that MikroTik RouterOS which has a large MTU size standard of each interface. In RouterOS for MTU is divided into several types: MTU L3 (IP / Layer-3), L2.5 MTU (MPLS / Layer2.5), L2 MTU (MAC / Layer-2), Full Frame MTU. Of the types of MTU, has a different standard. The reason why some packets might not get forwarded is that MikroTik devices running RouterOS by default has MTU set to 1500 and L2MTU set to something around 1580 bytes (depends on the device), but the Ethernet interface will silently drop anything that does not fit into the L2MTU size. By default, MSS is chosen as MTU of the outgoing interface minus the usual size of the TCP and IP headers (40 bytes), which results in 1460 bytes for an Ethernet interface. Unfortunately, there may be intermediate links with lower MTU which will cause fragmentation. In such a case TCP stack performs path MTU discovery. Jul 22, 2018 · Certamente se você usa PPPoE já teve a dúvida de saber qual o melhor MTU para colocar nos seus clientes, se é 1492, 1480, 1452 Veja nesse vídeo exatamente
Ensure MTU settings in router & PC (if you ever changed it) are 1500. ping with. ping -f -l nnnn bbc.co.uk. Find largest nnnn for which it doesn't need fragmentation. Then add 28 to get MTU. Vigor 130 is RFC 4638 compliant (Baby Jumbo Frames) MTU = 1508. BT uses (VLAN) tag 101. therefore, PC Ethernet interface is set to 1500
MTU and TCP-MSS Configuration On a Mikrotik router the TCP-MSS gets picked up and set in a mangle rule. For this example we will set the MSS for traffic going over the PPPoE interface. We will set the MSS at 1452 which is calculated as per below: MSS = MTU of interface - TCP Header - IP Header MSS = 1492 - 20 - 20 MSS = 1452 Feb 15, 2020 · MikroTik announced VxLAN support on Valentine’s Day (Feb 14th) of 2020. This is a significant feature addition for RouterOSv7 as it will pave the way for a number of other additions like EVPN in BGP. It will also give MikroTik the ability to appeal to enterprises and data centers that might need cost-effective VxLAN capable devices. Nov 28, 2016 · Add 28 to that number (IP/ICMP headers) to get the optimal MTU setting. For example, if the largest packet size from ping tests is 1462, add 28 to 1462 to get a total of 1490 which is the optimal MTU setting. Change the MTU on the routers WAN Setup.
Nov 28, 2016 · Add 28 to that number (IP/ICMP headers) to get the optimal MTU setting. For example, if the largest packet size from ping tests is 1462, add 28 to 1462 to get a total of 1490 which is the optimal MTU setting. Change the MTU on the routers WAN Setup.
Mikrotik RouterOS recognizes several types of MTU: IP/Layer-3/L3 MTU; MPLS/Layer-2.5/L2.5 MTU; MAC/Layer-2/L2 MTU; Full frame MTU; Full frame MTU. Full frame MTU represents the actual size of the frame that is sent by a particular interface. The value cannot be monitored and it is not configurable through RouterOS. Full frame MTU. Full frame MTU indicates the actual size of the frame that is sent by a particular interface. Frame Checksum is not included as it is removed by an ethernet driver as soon as it reaches its destination. MAC/Layer-2/L2 MTU. L2MTU indicates the maximum size of the frame without the MAC header that can be sent by this interface. So also on systems that MikroTik RouterOS which has a large MTU size standard of each interface. In RouterOS for MTU is divided into several types: MTU L3 (IP / Layer-3), L2.5 MTU (MPLS / Layer2.5), L2 MTU (MAC / Layer-2), Full Frame MTU. Of the types of MTU, has a different standard. The reason why some packets might not get forwarded is that MikroTik devices running RouterOS by default has MTU set to 1500 and L2MTU set to something around 1580 bytes (depends on the device), but the Ethernet interface will silently drop anything that does not fit into the L2MTU size. By default, MSS is chosen as MTU of the outgoing interface minus the usual size of the TCP and IP headers (40 bytes), which results in 1460 bytes for an Ethernet interface. Unfortunately, there may be intermediate links with lower MTU which will cause fragmentation. In such a case TCP stack performs path MTU discovery. Jul 22, 2018 · Certamente se você usa PPPoE já teve a dúvida de saber qual o melhor MTU para colocar nos seus clientes, se é 1492, 1480, 1452 Veja nesse vídeo exatamente MikroTik is a Latvian company which was founded in 1996 to develop routers and wireless ISP systems. MikroTik now provides hardware and software for Internet connectivity in most of the countries around the world.