0 votes 0 votes When the IP packet has minimum size (20bytes), what happens to option field. Is it not present or present with all bits set to 0 (all 40bytes of 0's)? Computer Networks computer-networks ip-packet + – Mayank Joshi asked Sep 6, 2017 Mayank Joshi 753 views answer comment Share Follow See 1 comment See all 1 1 comment reply prateekdwv commented Sep 6, 2017 reply Follow Share The bits of Options field are not present at all. A host identifies the presence of Options field from IHL(Internet Header Length) bits. If IHL is 5 (minimum header length), it will expect Payload exactly after 20 bytes of header. Refer RFC 791 for more detailed information. 2 votes 2 votes Please log in or register to add a comment.
Best answer 1 votes 1 votes Option field in IP header is optional, i.e. if we look at IP packet of 20 bytes it wont be having any option field or data field .. Is it not present or present with all bits set to 0 (all 40bytes of 0's)? Even if you set all those option field bits to 0 ,it will consume the space . Hence it wont be having that 20bytes size. I guess it answer the second part. Satyajeet Singh answered Sep 8, 2017 selected Dec 17, 2017 by Mayank Joshi Satyajeet Singh comment Share Follow See all 0 reply Please log in or register to add a comment.