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* mbuf data is 1400 bytes but the most common (?) use, Ethernet II frames, allow for 1518 bytes
@ 2023-10-04  6:52 Nicolson Ken (ニコルソン ケン)
  2023-10-04  7:19 ` Dmitry Kozlyuk
  0 siblings, 1 reply; 3+ messages in thread
From: Nicolson Ken (ニコルソン ケン) @ 2023-10-04  6:52 UTC (permalink / raw)
  To: users

Hi all,

Looking at sending Ethernet packets over a DPDK connection, I see that an Ethernet Type II frame has 1518 max, but mbuf's data block is 1400 bytes.

Is this what the headroom and tailroom are for? I see example code that uses the headroom for the MAC Header, but what is the preferred way of copying a 1518 Ethernet packet into an mbuf? Should I use rte_pktmbuf_append() to reserve the extra bytes, or is there a better way?

Thanks,
Ken


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2023-10-05  2:28 UTC | newest]

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2023-10-04  6:52 mbuf data is 1400 bytes but the most common (?) use, Ethernet II frames, allow for 1518 bytes Nicolson Ken (ニコルソン ケン)
2023-10-04  7:19 ` Dmitry Kozlyuk
2023-10-05  2:28   ` Nicolson Ken (ニコルソン ケン)

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