Experimental Values In IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP Headers
Extracted elements (20)
Although RFC 3692 states it may not be necessary to allocate UDP and TCP port values for experimentation, this document explicitly reserves ports 1021 and 1022 to avoid any possible conflict between experiments.
IPv4 Traffic Class Pool 2 (code points xxxx11) is already defined as Experimental/Local Use by RFC 2474, and the ECN field has no free code points, so no additional experimental code points are needed in those fields.
IPv4 addresses from RFC 1918 private ranges may be useful for certain experiments, but other special-purpose IPv4 addresses (RFC 3330) must not be used for experimentation.
The documentation prefix (RFC 3849) must not be used for IPv6 experimentation. Unique Local Addresses (RFC 4193) may be useful for certain experiments.
Experimental values MUST NOT be shipped as defaults in implementations. They are only appropriate to use in explicitly-configured experiments.
The IPv6 multicast group FF0X::114 is set aside for experimentation at all scope levels. Smaller scopes are particularly useful because they are defined not to leak outside a given boundary.
A single IPv4 Option Number (30) is assigned for experimentation, with all combinations of 'copy' (0 or 1) and 'class' (0 or 2) fields yielding four distinct option type codes: 30, 94, 158, and 222.
Eight IPv6 Hop-by-Hop and Destination Option Type codes are assigned for experimentation, covering all combinations of 'act' and 'chg' fields with the low-order 5 bits set to 11110 (hex values 0x1e, 0x3e, 0x5e, 0x7e, 0x9e, 0xbe, 0xde, 0xfe).
ICMPv4 type numbers 253 and 254 are reserved for RFC3692-style experimentation (Experiment 1 and Experiment 2 respectively).
IPv4 multicast group 224.0.0.254 (link-local scoped) and relative group address 254 (scope-relative) are assigned for RFC3692-style experimentation.
IPv4 Protocol field code points 253 and 254 are allocated for experimentation, as assigned by RFC 3692.
IPv6 Neighbor Discovery Option Types 253 and 254 are assigned for RFC3692-style experimentation.
IPv6 Next Header field code points 253 and 254 are allocated for experimentation, as assigned by RFC 3692.
IPv6 Routing Header Routing Type values 253 and 254 are assigned for RFC3692-style experimentation.
System ports 1021 and 1022 (both UDP and TCP) are reserved for RFC3692-style experimentation, designated as exp1 and exp2 respectively.
TCP Option Kind values 253 and 254 (variable length N) are reserved for RFC3692-style experimentation with TCP options.
Production networks may not support experimental code points; the network scope must be carefully evaluated before deploying experiments across extended domains such as the public Internet, as unsupported experimental code points could disrupt stable network operation.
Security analyzers (firewalls, IDS) rely on unambiguous field interpretations; unrecognized experimental values may cause them to drop traffic (loss of connectivity) or forward it unchecked (loss of security). Assigning known experimental values allows analyzers to take a defined action.
The experimental IPv4 options defined in Section 2.5 are not included in IPsec AH calculations, making it impossible to authenticate their use. For IPv6 experimental options, the 'chg' field value determines whether the option is included in AH calculations.
When experimental code points are used across multiple administrative domains, experimenters must assume that the same code points may be used simultaneously by other experiments, creating interference and potential security threats.