enable config t
no ip domain-lookup
hostname
TTL:
64 Linux
128 windows
255 cisco ios
OSI -
Physical data network transport session presentation application
Please Do Not Throw Sausage Pizza Away
People dont need those stupid packets anyway
arp - mac
DORA discover offer request acknowledge
/24 = 254 addresses
/30 = 4 addresses, router to router
on routers:
ip route [destination network] [mask] [next hop IP]
R1->R2
R1(config)# ip route 10.0.10.0 255.255.255.0 10.0.0.2
R1(config)# ip route 10.0.20.0 255.255.255.0 10.0.0.2
R2->R1
R2(config)# ip route 192.168.10.0 255.255.255.0 10.0.0.1
R2(config)# ip route 192.168.20.0 255.255.255.0 10.0.0.1
show ip route
show ip ospf neighbor
OSPF ->
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
network 192.168.10.0 0.0.0.255 area 0
network 192.168.20.0 0.0.0.255 area 0
network 10.0.0.0 0.0.0.3 area 0
network 10.0.1.0 0.0.0.3 area 0
ip access-list extended NAME
deny ip source ip source wildcard mask destination ip destination wildcard mask
15 deny ip 192.168.10.0 0.0.0.255 10.0.10.0 0.0.0.255 (with ID)
/24 255.255.255.0 254
/25 255.255.255.128 126
/26 255.255.255.192 62
/27 255.255.255.224 30
/28 255.255.255.240 14
/29 255.255.255.248 6
/30 255.255.255.252 2
Hosts = 2^(32-prefix) - 2. The -2 is always for network and broadcast address.
Example: 192.168.10.0/26
Mask = 255.255.255.192
Block size = 256 - 192 = 64
Subnets start at: 0, 64, 128, 192
Your IP 192.168.10.0 falls in the 0 block
Network: 192.168.10.0
Broadcast: 192.168.10.63 (next block - 1)
Hosts: 192.168.10.1 → 192.168.10.62
IPv4: 192.168.10.11
IPv6: 2001:0db8:85a3:0000:0000:8a2e:0370:7334
10.10.10.200/28 - network address, broadcast, host range.
/28 is 240, 256-240 is 16
0 16 32 48 64 80 96 112 128 144 160 176 192 208 etc
so its in block 192
network is 10.10.10.192 broadcast is 10.10.10.207 and host range is 193-206
IPv4: 192.168.10.11
IPv6: 2001:0db8:85a3:0000:0000:8a2e:0370:7334
Rule 1 leading zeros in a group can be dropped:
0db8 -> db8
0000 -> 0
Rule 2 one consecutive run of all-zero groups can be replaced with ::
2001:0db8:0000:0000:0000:0000:0370:7334
-> 2001:db8::370:7334
Global Unicast starts with 2001: the public internet addresses, routable everywhere. Equivalent to public IPv4.
Link-Local starts with fe80: automatically assigned to every IPv6 interface, only valid on the local segment, never routed. Every device has one regardless of any other config. Used for NDP and routing protocol hellos.
Loopback ::1 equivalent to 127.0.0.1 in IPv4.
SLAAC (Stateless Address Autoconfiguration)
2001:db8:acad:10::1/64
network prefix :: host