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What is the PPPoE MTU size?
1492 bytes
PPPOE interfaces generally have an MTU of 1492 bytes, whereas the straight Ethernet interface that they sit on have an MTU of 1500 bytes.
What is the maximum transmission size using PPPoE?
For a PPPoE interface, the PPPoE header uses 6 bytes and the PPP protocol ID uses 2 bytes. This restricts the maximum receive unit (MRU) size on a PPPoE interface to 1492 bytes, which can cause frequent fragmentation and reassembly of larger PPP packets received over the PPPoE interface.
What is MRU and MTU?
MTU (maximum transmission unit) & MRU (maximum receive unit)
What is the best MTU for gaming?
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.
What should the MTU be for a PPPoE connection?
The MTU size includes the data payload, any transport headers (such as TCP, UDP, GRE, RTP, or ICMP), and the IP header. It is generally recommended that the MTU for a WAN interface connected to a PPPoE DSL network be 1492. In fact, with auto MTU discovery, 1492 is discovered to be the maximum allowed MTU.
How to calculate the MTU of an IP ping?
What goes inside the payload of the frames depends on what you are doing. If you are pinging an IP, it would be a ICMP packet inside an IP packet so to figure out the largest ICMP packet size you can use, you subtract the size of the IP header (20 bytes 2) and the ICMP header ( 8 bytes) from the MTU: 1500 – 20 – 8 = 1472.
How big is a ping when using PPPoE?
That is unless you’re connecting over PPPoE. If you are using PPPoE you will find that your ping will fail with a packet size of 1472. This is because PPPoE has its own packet header of 8 bytes. If you subtract the PPPoE header from our previous value you will get the actual largest ICMP packet size: 1472 – 8 = 1464.
How can I optimize PPPoE connection size?
Having an MTU of 1500 allows for 1460 bytes of data payload, 20 bytes of TCP header, and 20 bytes of IP header. With PPPoE connections, the PPP and PPPoE header increases the frame size by 8 bytes, so we must lower the MTU to 1492. With the ethernet header added to this, we get a frame size of 1518 bytes.