Network port number; why 16-bit has 65535, not 65536? The port number is a representation of bit in base 2 2 power of 16 equal to 65536: It is the amount of numbers in base 2 that can be created with 16 bits, the number 65536 does not represent the last number that can be created in base 2 with 16 bits In base 2, first number is 0000,0000,0000,0000 , in base 10 is 0
How is 65535 bytes is total length of IP datagram? The maximum size of an IPv4 packet is 65,535 because the Total Length field is a 16-bit unsigned integer, which has a possible 65,536 values (from 0 to 65,535) This created 2 confusions for me Say we have 1 bit number Then there are 2 possible values 0 and 1 Say, each value occupies 1 byte in memory
Sonicwall NAT pooling PAT SNAT state table exhaustion There is a maximum of 65536 ports per address, and two ports are used per state, so 65536 2 = 32768, with separate tables for each protocol of TCP, UDP, and ICMP Networks with a sufficiently large number of users can start experiencing random state exhaustion events during periods of high load
Why BGP max message size is choosen as 4096 ? why not 2^16? 65536 4096 = 16 Do we really want BGP's transient RAM requirements to multiply by 16? Remember that under the covers, many BGP implementations are written in C, which means BGP could need to malloc space for every message to the maximum message size Obligatory rhetorical questions Why do we have any variable size limits in software?
range of AS numbers which are given out by RIRs 0 - reserved ASN 23456 - AS_TRANS 64496 - 64511 - reserved for documentation 64512 - 65534 - private ASN 65535 - reserved ASN 65536 - 65551 - reserved for documentation 4200000000 - 4294967294 - private ASN 4294967295 - reserved ASN
TAC Response on the error( %SYS-2-MALLOCFAIL: Memory allocation) The most common reason I've seen for alloc failures has been serious misconfiguration of the default route -- ip route 0 0 0 0 0 0 0 0 f0 0 will cause this because it's proxy-arp, and the ARP table will grow to an insane size
IPv4 maximum datagram size - Network Engineering Stack Exchange The maximum size of an IPv4 packet is 65,535 because the Total Length field is a 16-bit unsigned integer, which has a possible 65,536 values (from 0 to 65,535) The maximum payload is 65,515 only if the header is 20 If the header is 60, then you must subtract 40 from that because the total packet size cannot exceed 65,535
Purpose of the Transport Layer from a Conceptual Perspective For example, TCP and UDP have up to 65536 addresses (ports) each, to which processes may attach Other layer-4 protocols can allow more, or less, processes to attach You can also have different layer-4 protocols, which serve different purposes, (e g connection-oriented, connectionless, custom for a specific purpose, etc )
Does the NAT source UDP port depend only on src ip port? So yes, with a theoretical maximum of 65536 PAT entries, 1 device with 65536 outgoing connections from different src-ports, or one src-port from 65536 devices, could fill up the translation table In practice , that limit might be reduced by:
Where is the maximum packet size for TCP identified as 65,535? "IP has a "TCP Length" field" No, it doesn't IP doesn't know anything about TCP The IPv4 header has a 16-bit Total Length field that specifies the length of the entire IPv4 packet, including the IPv4 header and the payload (which may include a TCP segment)