Subject: Re: ip_flow.c
To: Kevin M. Lahey <>
From: Don Lewis <>
List: tech-net
Date: 01/29/1999 02:44:17
On Jan 29,  2:25am, Andrew Brown wrote:
} Subject: Re: ip_flow.c

} 1812 allows incremental updating.  it doesn't exactly encourage it,
} but it does say it's allowed.

In one way, I prefer incremental updating to recalculating the checksum.
If something gets stomped on, the next hop is likely to toss the packet
if the checksum was incrementally updated,  but if the damage occurred
before a full checksum recalculation, the next hop will accept the
corrupted packet.

This is similar to the reason that a bridge should not regenerate the
Ethernet CRC on outgoing packets.