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Linux Networking #2. Dr. Michael L. Collard www.sdml.info/collard www.sdml.info/collard/linux collard@cs.kent.edu. Network Configuration. /etc/network/interfaces Used by ifup, ifdown NetworkManager replaces this. # The loopback interface auto lo iface lo inet loopback
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Linux Networking #2 Dr. Michael L. Collard www.sdml.info/collard www.sdml.info/collard/linux collard@cs.kent.edu
Network Configuration • /etc/network/interfaces • Used by ifup, ifdown • NetworkManager replaces this # The loopback interface auto lo iface lo inet loopback # The first network card auto eth0 iface eth0 inet static address 131.123.42.38 netmask 255.255.255.224 broadcast 131.123.42.63 gateway 131.123.42.33 # dhcp iface eth1 inet dhcp
Routing • Typically use a dedicated router as a gateway • Computer as a gateway: • routed daemon – Uses RIP (Routing Information Protocol) • GNU Zebra – Uses RIP, OSPF (Open Shortest Path First), and BGP (Border Gateway Protocol)
Name Service • Translates names to IP addresses • DNS (Domain Name System) • BIND (Berkerly Internet Name Domain) name server • de facto standard open source name server • named BIND server • Clients: • dig • host
NFS (Network File System) • Distributed file system • Server – nfsd • exportfs, /etc/export – exported directories • /etc/hosts.allow, /etc/hosts.deny • nfsd • Client • mounts exported directory • mount servername:/projects /mnt/nfs/projects • Typically automounted
NIS (Network Information System) • Client-server directory service protocol for distributing system configuration data (user and host names) • Originally called: Yellow Pages (YP) • ypserv – server daemon • ypbind – client program • Integrated into system password operations
NIS+ • Sun replacement for NIS, implementation different from NIS • hierarchical • based Secure RPC (servers must authenticate clients and vice-versa) • may be replicated read-only • finer-grained permissions on data and operations • Sun recommends to switch to LDAP (Lightweight Directory Access Protocol)
Firewalls • Secure computer between an internal network and an external network • Set of rules – chains • netfilter – hooks in Linux kernel for filtering packets • iptables – set up, maintain, and list IP packet filter rules