route

manipulate network routing tables

BSD i.e. Mac £inux

route [-dnqtv] command [[modifiers] args]
route [-n] command [-net | -host] destination gateway [netmask]

-n numeric addresses only. No name lookups.
-d debug mode, Do not modify the routing table.
-t test mode. use /dev/null instead of a socket.
-v verbose
-q quite Suppress all output.

Commands:

get host display the route for a destination.

route -n get 192.0.43.10 # ( example.com )
   route to: 192.0.43.10
destination: default
       mask: default
    gateway: 192.168.1.1 (shows a gateway)
  interface: en1
      flags: <UP,GATEWAY,DONE,STATIC,PRCLONING>
 recvpipe  sendpipe  ssthresh  rtt,msec    rttvar  hopcount      mtu     expire
       0         0         0         0         0         0      1500         0 
monitor report any changes to the routing information base, routing lookup misses, or suspected network partitionings.
Sleeps wakes and checks,…
smacpro 5/12/20 ( as a set i.e. all timestams are the same. this repeates every 15 seconds)
got message of size 112 on Tue May 12 12:19:43 2020
timestamps removed
RTM_IFINFO: iface status change: len 112, if# 5, flags:<UP,BROADCAST,b6,RUNNING,PPROMISC,SIMPLEX,MULTICAST> 
RTM_IFINFO: iface status change: len 112, if# 5, flags:<UP,BROADCAST,b6,RUNNING,SIMPLEX,MULTICAST>

RTM_IFINFO: iface status change: len 112, if# 12, flags:<UP,PTP,RUNNING,PPROMISC,MULTICAST> 
RTM_IFINFO: iface status change: len 112, if# 12, flags:<UP,PTP,RUNNING,MULTICAST>

RTM_IFINFO: iface status change: len 112, if# 1, flags:<UP,LOOPBACK,RUNNING,PPROMISC,MULTICAST> 
RTM_IFINFO: iface status change: len 112, if# 1, flags:<UP,LOOPBACK,RUNNING,MULTICAST>

RTM_IFINFO: iface status change: len 112, if# 9, flags:< BROADCAST,RUNNING,SIMPLEX,MULTICAST> 

got message of size 68 on RTM_DELMADDR: multicast group membership removed from iface: len 68,
                         sockaddrs: GATEWAY,IFP,IFA> 
                         1.0.5e.0.0.1 en0:4c.32.75.97.3b.ad 224.0.0.1

RTM_DELETE: Delete Route: len 128, pid: 153, seq 72, errno 3, 
                                    ifscope 1, ifref, flags:<UP,HOST,DONE,LLINFO,WASCLONED,LOCAL,IFSCOPE,IFREF>
    locks:  inits:
    sockaddrs: <DST,GATEWAY>
    192.168.1.46 4c.32.75.97.3b.ad

RTM_DELETE: Delete Route: len 128, pid: 153, seq 74, errno 0, 
                                    ifscope 5, flags:<HOST,DONE,WASCLONED,BROADCAST,IFSCOPE,CONDEMNED>
    locks:  inits:
    sockaddrs: <DST,GATEWAY>
    192.168.1.255 ff.ff.ff.ff.ff.ff

RTM_DELETE: Delete Route: len 164, pid: 153, seq  , errno 0, 
                                     flags:<HOST,DONE,STATIC,b016,WASCLONED,CONDEMNED>
    locks:  inits:
    sockaddrs: <DST,GATEWAY,IFP,IFA>
 169.254.8.239 78.4f.43.50.8a.13 en0:4c.32.75.97.3b.ad 192.168.1.46
 …
 germansfios_g1100.germans 20.c0.47.c2.a8.a3 en0:4c.32.75.97.3b.ad 192.168.1.46
 …
 pycom 80.7d.3a.94.7b.7c en0:4c.32.75.97.3b.ad 192.168.1.46
… …
RTM_NEWADDR: address being added to iface: len 80, metric 0, flags:CLONING
sockaddrs: NETMASK,IFP,IFA,BRD>
 255.255.255.0 en0:4c.32.75.97.3b.ad smacpro.germans 192.168.1.255
… …
add
delete
change Change aspects of a route (such as its gateway).
In change or add where the destination and gateway are not sufficient to specify the route (as in the ISO case where several interfaces may have the same address), -ifp or -ifa may be used to determine the interface or interface address.
flush [family] Remove [all] routes.
address families -osi, -xns, -atalk, -inet6, or -inet modifiers, only routes having destinations with addresses in the delineated family will be deleted.

gateway is the next-hop intermediary via which packets should be routed.
Routes to a particular host may be distinguished from those to a network by interpreting the Internet address specified as the destination argument.

-net
-host
force the destination.
If the destination has a local address part of INADDR_ANY (0.0.0.0), or
if the destination is the symbolic name of a network, then the route is assumed to be to a network; otherwise, it is presumed to be a route to a host.
The destination could also be specified in the CIDR net/bits format.

examples:

128.32 -host 128.0.0.32
128.32.130 -host 128.32.0.130
-net 128.32 128.32.0.0
-net 128.32.130 128.32.130.0
192.168.64/20 -net 192.168.64 -netmask 255.255.240.0 `

A destination default is a synonym for -net 0.0.0.0.

-interface destination is directly reachable via an interface requiring no intermediary system to act as a gateway.
gateway is the address of this host on the common network, indicating the interface to be used for transmission.
If the interface is point to point, the name of the interface itself may be given, in which case the route remains valid even if the local or remote addresses change.
-xns
-osi
-link
subsequent addresses are in the XNS, OSI, or AppleTalk address families, or are specified as link-level addresses.
Must be numeric.
-netmask manually add subnet routes with netmasks different from that of the implied network interface (as would otherwise be communicated using the OSPF or ISIS routing protocols). Specify additional address parameter (to be interpreted as a network mask).
In the AF_INET case, the implicit network mask generated can be overridden by making sure this option follows the destination parameter.

For AF_INET6, -prefixlen is available instead of -mask because non-continuous masks are not allowed in IPv6. For example, -prefixlen 32 specifies network mask of ffff:ffff:0000:0000:0000:0000:0000:0000 to be used.
The default value of prefixlen is 64 to get along with the aggregatable address.
0 is assumed if default is specified.

-rtt
-rttvar
-sendpipe
-recvpipe
-mtu
-hopcount
-expire
-ssthresh
provide initial values to quantities maintained in the routing entry by transport level protocols, such as TCP or TP4. These may be individually locked by preceding it locked by the -lock meta-modifier, or specify that all ensuing metrics may be locked by the -lockrest meta-modifier.

-proxy the RTF_LLINFO routing table entry is the published (proxy-only) ARP entry, as reported by arp.

Flags

     -cloning   RTF_CLONING   generates a new route on use
     -xresolve  RTF_XRESOLVE  emit mesg on use (for external lookup)
     -iface    ~RTF_GATEWAY   destination is directly reachable
     -static    RTF_STATIC    manually added route
     -nostatic ~RTF_STATIC    pretend route added by kernel or daemon
     -reject    RTF_REJECT    emit an ICMP unreachable when matched
     -blackhole RTF_BLACKHOLE silently discard pkts (during updates)
     -proto1    RTF_PROTO1    set protocol specific routing flag #1
     -proto2    RTF_PROTO2    set protocol specific routing flag #2
     -llinfo    RTF_LLINFO    validly translates proto addr to link addr 
All symbolic names specified for a destination or gateway are looked up first as a host name using gethostbyname.
If this lookup fails, getnetbyname is then used to interpret the name as that of a network.

Route uses a routing socket and the new message types: RTM_ADD, RTM_DELETE, RTM_GET, and RTM_CHANGEL.

Errors

add |delete [ host | network ] %s: gateway %s flags %x
If the gateway address used was not the primary address of the gateway (the first one returned by gethostbyname(3))

With flush, each entry deleted is indicated with a message of this form: %s %s done

Network is unreachable An attempt to add a route failed because the gateway listed was not on a directly-connected network. The next-hop gateway must be given.

not in table A delete operation was attempted for an entry which wasn't present in the tables.

routing table overflow An add operation was attempted, but the system was unable to allocate memory to create the new entry.

gateway uses the same route A change resulted in a route whose gateway uses the same route as the one being changed. The next-hop gateway should be reachable through a different route.

Display Routing tables mac os

05/12/20
/usr/sbin/netstat -r
Routing tables

Internet:
Destination        Gateway            Flags        Netif Expire
default            germansfios_g1100. UGSc           en0       
127                localhost          UCS            lo0       
localhost          localhost          UH             lo0       
169.254            link#5             UCS            en0      !
192.168.1          link#5             UCS            en0      !
192.168.1.1/32     link#5             UCS            en0      !
germansfios_g1100. 20:c0:47:c2:a8:a3  UHLWIir    en0   1181
hpc658ca.germans   10:60:4b:c6:58:ca  UHLWI      en0   1091
slammerfox.germans 50:3e:aa:d:46:e9   UHLWIi     en0   1143
192.168.1.11       a8:10:87:18:67:37  UHLWI      en0   1091
dapi2.germans      b8:27:eb:f0:ae:8   UHLWI      en0   1096
kitchen.germans    70:85:c2:63:1f:bf  UHLWI      en0   1199
pi93graf.germans   b8:27:eb:1c:5b:93  UHLWI      en0   1096
tesla_model_s.germ 4:4e:af:ac:8:e1    UHLWI      en0   1097
denniss-iphone.ger f8:e9:4e:e2:89:16  UHLWI      en0   1091
fing.germans       f0:23:b9:eb:2b:88  UHLWI      en0   1200
marilyns-iphone.ge d4:61:da:c1:83:df  UHLWIi     en0   1199
esp_2116b0.germans 84:f3:eb:21:16:b0  UHLWI      en0   1091
damonitor2.germans b8:27:eb:6:73:4c   UHLWI      en0   1096
192.168.1.44/32    link#5             UCS        en0      !
smacpro.germans    4c:32:75:97:3b:ad  UHLWI          lo0       
192.168.1.61       b8:27:eb:f7:1d:5a  UHLWI      en0   1096
STB                0:1f:c4:ef:5d:f1   UHLWI      en0   1091
224.0.0/4          link#5             UmCS       en0      !
224.0.0.251        1:0:5e:0:0:fb      UHmLWI     en0       
239.255.255.250    1:0:5e:7f:ff:fa    UHmLWI     en0       
255.255.255.255/32 link#5             UCS        en0      !
 long delay

Exits 0 on success, and >0 if an error occurs.
         

See netintro, arp, routed