http://www.systemengineers.de/ 2010-09-09T06:32:40+02:00 http://www.systemengineers.de/ http://www.systemengineers.de/lib/images/favicon.ico text/html 2009-09-12T12:46:12+02:00 http://www.systemengineers.de/cisco/config/access-lists?rev=1252752372 The access list is a group of statements. Each statement defines a pattern that would be found in an IP packet. As each packet comes through an interface with an associated access list, the list is scanned from top to bottom--in the exact order that it was entered--for a pattern that matches the incoming packet. A permit or deny rule associated with the pattern determines that packet's fate. You also can use a mask, which is like a wild card, to determine how much of an IP source or destination … text/html 2009-09-12T12:46:12+02:00 http://www.systemengineers.de/cisco/config/dsl-as-backup-line?rev=1252752372 DSL and cable are both becoming popular options for backup links since they aren’t very expensive, and are routinely much higher speed than ISDN dial-up lines. Both cable and DSL connect to some sort of modem usually, and then are plugged into an Ethernet card. Certain routers can interface with DSL lines directly (a WIC-1ADSL for your Cisco Router for example). Once the connection is complete, you typically have a single IP address available to you. (This can be negotiated differently with y… text/html 2009-09-12T12:46:12+02:00 http://www.systemengineers.de/cisco/config/dsl_backup?rev=1252752372 Diese Konfig ist aus einer T-Online ADSL Konfig entstanden. Bei anderen Providern müssen eventuell Änderungen vorgenommen werden bzw. ist es nicht sichergestellt das diese Konfiguration funktioniert. Um eine derartige Konfig zum laufen zu bekommen ist ein wenig Vorarbeit nötig. Ihr müßt zuerst die IP-Adresse des ISP-Dialin-Gateways herausbekommen. Diese wird dann im Abschnitt „hier kommt die ip vom next hop rein die via ipcp zuwiesen wurde“. Um die IP zu ermittlen geht ihr wie folgt vo… text/html 2009-09-12T12:46:12+02:00 http://www.systemengineers.de/cisco/config/eigrp-the-enhanced-interior-gateway-routing-protocol?rev=1252752372 Enhanced Interior Gateway Routing Protocol (EIGRP) is an enhanced version of IGRP. IGRP is Cisco's Interior Gateway Routing Protocol used in TCP/IP and OSI internets. It is regarded as an interior gateway protocol (IGP) but has also been used extensively as an exterior gateway protocol for inter-domain routing. text/html 2009-09-12T12:46:12+02:00 http://www.systemengineers.de/cisco/config/einrichten-eines-gre-tunnel?rev=1252752372 Das Generic Routing Encapsulation (GRE) ist ein Netzwerkprotokoll, das von der Firma Cisco entwickelt wurde und im RFC 1701 definiert ist. Über GRE können andere Protokolle eingepackt werden und so in einem IP-Tunnel transportiert werden. Die Cisco Konfiguration text/html 2009-09-12T12:46:12+02:00 http://www.systemengineers.de/cisco/config/igrp-the-interior-gateway-routing-protocol?rev=1252752372 The Interior Gateway Routing Protocol (IGRP) is a routing protocol to provide routing within an autonomous system (AS). In the mid-1980s, the most popular interior routing protocol was the Routing Information Protocol (RIP). Although RIP was quite useful for routing within small- to moderate-sized, relatively homogeneous internetworks, its limits were being pushed by network growth. The popularity of Cisco routers and the robustness of IGRP encouraged many organizations with large internetworks … text/html 2009-09-12T12:46:12+02:00 http://www.systemengineers.de/cisco/config/kron_und_wiederkehrende_aufgaben_im_cisco_ios?rev=1252752372 Wiederkehrende Aktionen mit cron unter Linux oder at unter Windows kennt wohl jeder Admin. Es ist aber noch relativ unbekannt, dass im Cisco IOS seit Version 12.3(1) auch wiederkehrende Aktionen möglich sind. Die Konfiguration mit dem zuständigen Befehl Kron teilt sich in zwei Bereiche: text/html 2009-10-24T22:46:58+02:00 http://www.systemengineers.de/cisco/config/port-mirroring-auf-cisco-catalyst?rev=1256417218 Um einen Sniffer wie Wireshark oder ein IDS an einem Switch zu betreiben, benötigt der Adminstrator an diesem Switch einen Spiegelport. An diesen Port kann sämtlicher Traffic eines anderen Ports gespiegelt werden. Dieses Feature wird auch SPAN-Port, Monitor Port und Mirror Port genannt. text/html 2009-10-31T16:45:06+02:00 http://www.systemengineers.de/cisco/config/qos-on-adsl-line?rev=1257003906 QoS onto 1 VLAN if you want to put a shaper or any form of Qos onto a DSL router, you need to do it via an ATM subinterface, so it looks like: interface ATM0 description $ES_WAN$ no ip address no ip redirects no ip unreachables no ip proxy-arp ip route-cache flow no ip mroute-cache no atm ilmi-keepalive ! interface ATM0.1 point-to-point pvc 0/38 encapsulation aal5mux ppp dialer dialer pool-member 1 service-policy output shaper text/html 2009-09-12T12:46:12+02:00 http://www.systemengineers.de/cisco/config/qos?rev=1252752372 Zum Thema QoS gibt es ja bekanntlich viel Cisco Bücher. Ich möchte jetzt hier auch keine allzu ausführenden Konfigs einstellen, sondern nur Anhaltspunke liefern. Problemstellung 1 Ihr betreibt einen Webserver in eurem LAN und möchtet eine möglichst schnelle Reaktionszeit auf Requests haben. Außerdem soll der Webserver 80KBit an Bandbreite garantiert zur Verfügung haben. text/html 2009-09-12T12:46:12+02:00 http://www.systemengineers.de/cisco/config/vtp-the-vlan-trunking-protocol?rev=1252752372 VLAN Trunking Protocol (VTP) is a Cisco Layer 2 messaging protocol that manages the addition, deletion, and renaming of VLANs on a network-wide basis. Virtual Local Area Network (VLAN) Trunk Protocol (VTP) reduces administration in a switched network. When you configure a new VLAN on one VTP server, the VLAN is distributed through all switches in the domain. This reduces the need to configure the same VLAN everywhere. VTP is a Cisco-proprietary protocol that is available on most of the Cisco Cat… text/html 2009-09-12T12:46:12+02:00 http://www.systemengineers.de/cisco/config/wildcard-netmask?rev=1252752372 A hit on a topic that eludes many people throughout their networking career! (Kind of like the nuances of subnetting.) But in reality, it's not difficult at all! Remember that routers are just dumb binary devices. Life revolves around zeroes and ones! text/html 2009-09-12T12:46:12+02:00 http://www.systemengineers.de/cisco/config/zone-based-firewall?rev=1252752372 Cisco introduced Zone-based Policy Firewall since it’s 12.4(6) IOS release. It helps organizing firewall policies on multi-interface routers. This small tutorial will show how to set up a simple firewall policy on a router that interconnects three networks: