Makey@LOGICON.ARPA (Jeff Makey) (08/20/86)
If a gateway receives an IP segment whose time-to-live field has a
value of 1 (one), should it transmit the segment after decrementing the
TTL field to 0? RFC 791 (Internet Protocol) is not clear on this.
:: Jeff Makey
Makey@LOGICON.ARPAgmiller@CC6.BBN.COM (08/20/86)
Jeff, I am the tester for a BBNCC product called a Mailbridge. Mailbridges are a type of gateway. The way we have interpreted the TTL lower boundary condition is that 1 is the lower limit for the receiving device. For the case you stated, a datagram to be transmitted through a Mailbridge, 2 is the lowest limit for an incoming datagram. The datagram will be transmitted with TTL decremented to 1. Gerry Miller gmiller@CC6.BBN.COM
ron@BRL.ARPA (Ron Natalie) (08/21/86)
Likewise, the BRL gateways will discard incoming datagrams with packet counts of zero or one. Hence, any datagram that comes in with a TTL of Zero will be discarded and datagrams to be forwarded that have a time to live of zero after they've been decremented are discarded as well. The SPEC says that the packet will be discarded when the time to live is detected as being zero. We interpret that to mean at any time prior to transmission. -Ron