Dos- denial of services one of the problem faced 1999 which denied the user to use his/her intended resource
What has been done to Stop it
- input Debugging which is a kind of Link testing provided by different ( isps ) over upstream link of victims .Victim need to contact isp when found that they are been attacked by recognize the attack signature present in all . isp provide input debugging on there egress port
- Controlling flood test the link by flooding them with large bust of trafic and observing them how they perturb by attacker .Problem with this is router buffer are shared packet travelling across the load link included the link sent from attacker any need large topological mapping
- logging
- ICMP keeping the record of the package which are forwarding and having low probability
New technology or method in dis paper trackback ip by Stefan Savage, David Wetherall, Anna Karlin, and Tom Anderson based on algorithm node append and node sampling used for making nodes needed to keep the try under DOS
( where it consider p as probability and distance between router d hops so we have an monotonic function marked in red)
