[Internet-e-architetture-di-rete] genmask

[Antonio Prado]

ciao,

ricordo che ieri qualcuno chiedeva il significato di genmask.

genmask non appartiene al linguaggio delle interfacce dove, come sapete
si usa netmask per indicare la maschera di sottorete.

genmask si usa nell'ambito delle tabelle di routing degli host che non
usano il formato CIDR

esempi

#mac osx: Darwin Kernel Version 15.4.0
netstat -rn
Routing tables

Internet:
Destination        Gateway            Flags        Refs      Use   Netif
Expire
default            172.31.150.254     UGSc           18        0     en1
default            172.31.22.1        UGScI           0        0     en0
##########################################

#gnu/linux 3.13.0-85-generic
route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Iface
0.0.0.0         185.5.201.201   0.0.0.0         UG    100    eth0
185.5.200.0     0.0.0.0         255.255.254.0   U     0      eth0
##########################################

#FreeBSD 10.3-RELEASE
netstat -rn
Routing tables

Internet:
Destination        Gateway            Flags      Netif Expire
default            185.5.201.201      UGS        vmx0
127.0.0.1          link#2             UH          lo0
185.5.200.0/23     link#1             U          vmx0
185.5.201.241      link#1             UHS         lo0
192.175.48.0/24    link#1             U          vmx0
192.175.48.1       link#1             UHS         lo0
192.175.48.6       link#1             UHS         lo0
192.175.48.42      link#1             UHS         lo0
##########################################



#MS Windows7
route print
IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface
          0.0.0.0          0.0.0.0      172.31.22.1    172.31.22.141
        127.0.0.0        255.0.0.0         On-link         127.0.0.1
        127.0.0.1  255.255.255.255         On-link         127.0.0.1
  127.255.255.255  255.255.255.255         On-link         127.0.0.1
      172.31.22.0    255.255.255.0         On-link     172.31.22.141
    172.31.22.141  255.255.255.255         On-link     172.31.22.141
    172.31.22.255  255.255.255.255         On-link     172.31.22.141
        224.0.0.0        240.0.0.0         On-link         127.0.0.1
        224.0.0.0        240.0.0.0         On-link     172.31.22.141
  255.255.255.255  255.255.255.255         On-link         127.0.0.1
  255.255.255.255  255.255.255.255         On-link     172.31.22.141
#######trova l'intruso###################



ciao
--
antonio

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 163 bytes
Desc: OpenPGP digital signature
URL: <http://list.informagiovani.comunesbt.it/pipermail/internet-e-architetture-di-rete/attachments/20160419/03e083e7/attachment.bin>