Debian Bug 353161 (reported fixed in isc-dhcp 4.3.2-1) May 2015
Current package vyatta-dhcp3-relay 4.1.8+vyos1+helium2 (DHCPd also affected)
Produces the following log messages (level info):
Jan 2 12:28:45 10.10.64.3 dhcrelay: 4 bad udp checksums in 6 packets
Jan 2 12:28:51 10.10.64.3 dhcrelay: 4 bad udp checksums in 5 packets
Jan 2 12:28:53 10.10.64.3 dhcrelay: 4 bad udp checksums in 5 packets
Jan 2 12:28:55 10.10.64.3 dhcrelay: 4 bad udp checksums in 6 packets
Jan 2 12:28:56 10.10.64.3 dhcrelay: 4 bad udp checksums in 5 packets
Jan 2 12:28:58 10.10.64.3 dhcrelay: 4 bad udp checksums in 5 packets
Jan 2 12:29:03 10.10.64.3 dhcrelay: 4 bad udp checksums in 6 packets
Jan 2 12:29:03 10.10.64.3 dhcrelay: 4 bad udp checksums in 5 packets
Jan 2 12:29:10 10.10.64.3 dhcrelay: 4 bad udp checksums in 5 packets
Jan 2 12:29:21 10.10.64.3 dhcrelay: 4 bad udp checksums in 6 packets
Not sure how difficult building a post- 4.3.2-1 package will be on Squeeze.