|
Traceroute and Not-so-Equal ECMP
|
Si vous voulez bloquer ce service sur vos fils RSS
Si vous voulez nous contacter ou nous proposer un fil RSS
Menu > Articles de la revue de presse : - l'ensemble [ tous | francophone] - par mots clé [ tous] - par site [ tous] - le tagwall [ voir] - Top bi-hebdo de la revue de presse [ Voir]
Présentation : I came across an odd little issue recently involving equal-cost multipath ECMP routing and traceroute. Traceroutes from within our network to destinations out on the Internet were following two different paths, with one path being one hop longer than the other. This resulted in mangled traceroute output, impeding our ability to troubleshoot. The relevant network topology comprises a mesh of two edge routers and two core switches. Each edge router has a number of transit circuits to different providers, and advertises a default route via OSPF to the two core switches below. The core switches each load-balance traffic across both default routes to either edge routers. topology.png Because each edge router has different providers, some destinations are routed out via edge1 and others via edge2, which means sometimes a packet will be routed to edge2 via edge1, or vice versa. two_paths.png Routers typically employ a hash function using layer three and four information from each packet to pseudo-randomly distribute traffic across equal links. Typically, all packets belonging to a flow e.g. all packets with the same source and destination IP and port numbers follow the same path. However, in this case traceroute packets were being split across two path of unequal length, which made traceroute output pretty much unreadable. We noticed that only UDP traceroutes were affected ICMP traceroutes reported one path as normal. Continue reading No comments
Les derniers articles du site "PacketLife.net Blog" :
- Don't be Discouraged by Plagiarists
- Can You Keep a Secret Part 2
- Can You Keep a Secret
- Stretch's Hierarchy of Network Needs
- Thoughts on Two Years of Working from Home
- Writing a Custom IPAM Application
- What the CCIE does not Prove
- Traceroute and Not-so-Equal ECMP
- Networking FAQ 4 Fundamentals
- Networking FAQ 3 Names and Addresses
Menu > Articles de la revue de presse : - l'ensemble [ tous | francophone] - par mots clé [ tous] - par site [ tous] - le tagwall [ voir] - Top bi-hebdo de la revue de presse [ Voir]
Si vous voulez bloquer ce service sur vos fils RSS :
- avec iptables "iptables -A INPUT -s 88.190.17.190 --dport 80 -j DROP"
- avec ipfw et wipfw "ipfw add deny from 88.190.17.190 to any 80"
- Nous contacter par mail
Mini-Tagwall des articles publiés sur SecuObs : | | | | sécurité, exploit, windows, attaque, outil, microsoft, réseau, audit, metasploit, vulnérabilité, système, virus, internet, usbsploit, données, source, linux, protocol, présentation, scanne, réseaux, scanner, bluetooth, conférence, reverse, shell, meterpreter, vista, rootkit, détection, mobile, security, malicieux, engineering, téléphone, paquet, trames, https, noyau, utilisant, intel, wishmaster, google, sysun, libre |
Mini-Tagwall de l'annuaire video : | | | | curit, security, biomet, metasploit, biometric, cking, password, windows, botnet, defcon, tutorial, crypt, xploit, exploit, lockpicking, linux, attack, wireshark, vmware, rootkit, conference, network, shmoocon, backtrack, virus, conficker, elcom, etter, elcomsoft, server, meterpreter, openvpn, ettercap, openbs, iphone, shell, openbsd, iptables, securitytube, deepsec, source, office, systm, openssh, radio |
Mini-Tagwall des articles de la revue de presse : | | | | security, microsoft, windows, hacker, attack, network, vulnerability, google, exploit, malware, internet, remote, iphone, server, inject, patch, apple, twitter, mobile, virus, ebook, facebook, vulnérabilité, crypt, source, linux, password, intel, research, virtual, phish, access, tutorial, trojan, social, privacy, firefox, adobe, overflow, office, cisco, conficker, botnet, pirate, sécurité |
Mini-Tagwall des Tweets de la revue Twitter : | | | | security, linux, botnet, attack, metasploit, cisco, defcon, phish, exploit, google, inject, server, firewall, network, twitter, vmware, windows, microsoft, compliance, vulnerability, python, engineering, source, kernel, crypt, social, overflow, nessus, crack, hacker, virus, iphone, patch, virtual, javascript, malware, conficker, pentest, research, email, password, adobe, apache, proxy, backtrack |
|
|
|
|
|