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 address, i.e. do not display names, helpful with DNS problems

-d debug mode, Do not modify the routing table.
-t test mode. use /dev/null instead of a socket.
-n numeric addresses only. No name lookups. Translating from numerical to symbolic names is time consuming, and requires correct network operation. This is especially useful when attempting to repair networking.
-v verbose
-q quite Suppress all output.


get host display the route for a destination.

route -n get # ( )
   route to:
destination: default
       mask: default
    gateway: (shows a gateway)
  interface: en1
 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> 

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>

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> ff.ff.ff.ff.ff.ff

RTM_DELETE: Delete Route: len 164, pid: 153, seq  , errno 0, 
    locks:  inits:
    sockaddrs: <DST,GATEWAY,IFP,IFA> 78.4f.43.50.8a.13
 germansfios_g1100.germans 20.c0.47.c2.a8.a3
 pycom 80.7d.3a.94.7b.7c
… …
RTM_NEWADDR: address being added to iface: len 80, metric 0, flags:CLONING
sockaddrs: NETMASK,IFP,IFA,BRD> smacpro.germans
… …
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.
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.

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.

force the destination.
If the destination has a local address part of INADDR_ANY (, 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.


128.32 -host
128.32.130 -host
-net 128.32
-net 128.32.130
192.168.64/20 -net 192.168.64 -netmask `

A destination default is a synonym for -net

-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.
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.


     -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

-rtt, -rttvar, -sendpipe, -recvpipe, -mtu, -hopcount, -expire, and -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 one can specify that all ensuing metrics may be locked by the -lockrest meta-modifier.

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

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_CHANGE.


add [host | network ] %s: gateway %s flags %x The specified route is being added to the tables. The values output are from the routing table entry supplied in the ioctl(2) call.
If the gateway address used was not the primary address of the gateway (the first one returned by gethostbyname(3)), the gateway address is output numerically as well as symbolically.

delete [ host | network ] %s: gateway %s flags %x As above, but when deleting an entry.

%s %s done When the flush command is specified, each routing table entry deleted is indicated with a message of this form.

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 low on resources and was unable to allocate memory to create the new entry.

gateway uses the same route A change operation 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

/usr/sbin/netstat -r
Routing tables

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      !     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       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 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    link#5             UCS            en0      !
smacpro.germans    4c:32:75:97:3b:ad  UHLWI          lo0       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      !        1:0:5e:0:0:fb      UHmLWI         en0    1:0:5e:7f:ff:fa    UHmLWI         en0 link#5             UCS            en0      !

Destination        Gateway            Flags         Netif Expire
default            fe80::%utun0       UGcI          utun0       
default            fe80::%utun1       UGcI          utun1       
localhost          localhost          UHL             lo0       
fe80::%lo0         smacpro.local      UcI             lo0       
smacpro.local      link#1             UHLI            lo0       
fe80::%en0         link#5             UCI             en0       
smacpro.local      4c:32:75:97:3b:ad  UHLI            lo0       
hp10604bc658ca.loc 10:60:4b:c6:58:ca  UHLWI           en0       
fe80::%awdl0       link#10            UCI           awdl0       
fe80::3041:98ff:fe 32:41:98:2d:fe:b0  UHLI            lo0       
fe80::%llw0        link#11            UCI            llw0       
fe80::3041:98ff:fe 32:41:98:2d:fe:b0  UHLI            lo0       
fe80::%utun0       smacpro.local      UcI           utun0       
smacpro.local      link#12            UHLI            lo0       
fe80::%utun1       smacpro.local      UcI           utun1       
smacpro.local      link#13            UHLI            lo0       
ff01::%lo0         localhost          UmCI            lo0       
ff01::%en0         link#5             UmCI            en0       
ff01::%awdl0       link#10            UmCI          awdl0       
ff01::%llw0        link#11            UmCI           llw0       
ff01::%utun0       smacpro.local      UmCI          utun0       
ff01::%utun1       smacpro.local      UmCI          utun1       
ff02::%lo0         localhost          UmCI            lo0       
ff02::%en0         link#5             UmCI            en0       
ff02::%awdl0       link#10            UmCI          awdl0       
ff02::%llw0        link#11            UmCI           llw0       
ff02::%utun0       smacpro.local      UmCI          utun0       
ff02::%utun1       smacpro.local      UmCI          utun1
+++ Exits 0 on success, and >0 if an error occurs.

See netintro, arp, routed