10 KiB
Discover Infix Units
.----. Ethernet .-------.
| PC +---------------------+ Infix |
'----' if1 eth0 '-------'
Figure 1: PC directly connected over Ethernet to Infix unit (here eth0).
When you wish to discover the IP address of an Infix switch, the simplest way is probably to ping the IPv6 all-hosts address (ff02::1) over a directly connected Ethernet cable. The unit's link-local IPv6 address is seen in the response.
In the example below, the PC is connected to Infix via interface tap0 (tap0 is if1 in Figure 1) and Infix responds with address fe80::ff:fec0:ffed.
linux-pc:# ping -6 -L -c 3 ff02::1%tap0
PING ff02::1%tap0(ff02::1%tap0) 56 data bytes
64 bytes from fe80::ff:fec0:ffed%tap0: icmp_seq=1 ttl=64 time=0.558 ms
64 bytes from fe80::ff:fec0:ffed%tap0: icmp_seq=2 ttl=64 time=0.419 ms
64 bytes from fe80::ff:fec0:ffed%tap0: icmp_seq=3 ttl=64 time=0.389 ms
--- ff02::1%tap0 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2043ms
rtt min/avg/max/mdev = 0.389/0.455/0.558/0.073 ms
linux-pc:#
The PC could connect then connect to Infix, e.g., using SSH.
linux-pc:# ssh admin@fe80::ff:fec0:ffed%tap0
admin@fe80::ff:fec0:ffed%tap0's password: admin
admin@infix-c0-ff-ee:~$
Discovery mechanisms available in Infix
Infix advertises its presence via the mDNS and LLDP discovery protocols.
LLDP
Infix supports LLDP (IEEE 802.1AB). For a unit with factory default settings, the PC can readout the link-local IPv6 address from the Management Address TLV using tcpdump or other sniffing tools1 .
linux-pc:# tcpdump -i tap0 -Qin -v ether proto 0x88cc
tcpdump: listening on tap0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
15:51:52.061071 LLDP, length 193
Chassis ID TLV (1), length 7
Subtype MAC address (4): 02:00:00:c0:ff:ee (oui Unknown)
Port ID TLV (2), length 7
Subtype MAC address (3): 02:00:00:c0:ff:ee (oui Unknown)
Time to Live TLV (3), length 2: TTL 120s
System Name TLV (5), length 14: infix-c0-ff-ee
System Description TLV (6), length 91
Infix by KernelKit Linux 5.19.17 #1 SMP PREEMPT_DYNAMIC Wed Jun 7 08:47:23 CEST 2023 x86_64
System Capabilities TLV (7), length 4
System Capabilities [Bridge, WLAN AP, Router, Station Only] (0x009c)
Enabled Capabilities [Station Only] (0x0080)
Management Address TLV (8), length 24
Management Address length 17, AFI IPv6 (2): fe80::ff:fec0:ffed
Interface Index Interface Numbering (2): 2
Port Description TLV (4), length 4: eth0
Organization specific TLV (127), length 9: OUI IEEE 802.3 Private (0x00120f)
Link aggregation Subtype (3)
aggregation status [supported], aggregation port ID 0
Organization specific TLV (127), length 9: OUI IEEE 802.3 Private (0x00120f)
MAC/PHY configuration/status Subtype (1)
autonegotiation [none] (0x00)
PMD autoneg capability [unknown] (0x8000)
MAU type Unknown (0x0000)
End TLV (0), length 0
^C
1 packet captured
linux-pc:#
If the unit has an IPv4 address assigned, it is shown in an additional Management Address TLV.
Note
The Management Addresses shown by LLDP are not necessarily associated with the port transmitting the LLDP message.
In the example below, the IPv4 address (10.0.1.1) happens to be assigned to eth0, while the IPv6 address (2001:db8::1) is not.
linux-pc:# sudo tcpdump -i tap0 -Qin -v ether proto 0x88cc
tcpdump: listening on tap0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
15:46:07.908665 LLDP, length 207
Chassis ID TLV (1), length 7
Subtype MAC address (4): 02:00:00:c0:ff:ee (oui Unknown)
Port ID TLV (2), length 7
Subtype MAC address (3): 02:00:00:c0:ff:ee (oui Unknown)
Time to Live TLV (3), length 2: TTL 120s
System Name TLV (5), length 14: infix-c0-ff-ee
System Description TLV (6), length 91
Infix by KernelKit Linux 5.19.17 #1 SMP PREEMPT_DYNAMIC Wed Jun 7 08:47:23 CEST 2023 x86_64
System Capabilities TLV (7), length 4
System Capabilities [Bridge, WLAN AP, Router, Station Only] (0x009c)
Enabled Capabilities [Station Only] (0x0080)
Management Address TLV (8), length 12
Management Address length 5, AFI IPv4 (1): 10.0.1.1
Interface Index Interface Numbering (2): 2
Management Address TLV (8), length 24
Management Address length 17, AFI IPv6 (2): 2001:db8::1
Interface Index Interface Numbering (2): 3
Port Description TLV (4), length 4: eth0
Organization specific TLV (127), length 9: OUI IEEE 802.3 Private (0x00120f)
Link aggregation Subtype (3)
aggregation status [supported], aggregation port ID 0
Organization specific TLV (127), length 9: OUI IEEE 802.3 Private (0x00120f)
MAC/PHY configuration/status Subtype (1)
autonegotiation [none] (0x00)
PMD autoneg capability [unknown] (0x8000)
MAU type Unknown (0x0000)
End TLV (0), length 0
^C
1 packet captured
2 packets received by filter
0 packets dropped by kernel
linux-pc:#
The LLDP service can be disabled using the following commands.
admin@infix-c0-ff-ee:/> configure
admin@infix-c0-ff-ee:/config/> no lldp
admin@infix-c0-ff-ee:/config/> leave
admin@infix-c0-ff-ee:/>
mDNS
DNS-SD/mDNS can be used to discover Infix units and services. Infix units present their IP addresses, services and hostname within the .local domain. This method has good client support in Apple and Linux systems. On Linux, tools such as avahi-browse or mdns-scan2 can be used to search for devices advertising their services via mDNS.
linux-pc:# avahi-browse -ar
+ tap0 IPv6 infix-c0-ff-ee SFTP File Transfer local
+ tap0 IPv4 infix-c0-ff-ee SFTP File Transfer local
+ tap0 IPv6 infix-c0-ff-ee SSH Remote Terminal local
+ tap0 IPv4 infix-c0-ff-ee SSH Remote Terminal local
= tap0 IPv4 infix-c0-ff-ee SFTP File Transfer local
hostname = [infix-c0-ff-ee.local]
address = [10.0.1.1]
port = [22]
txt = []
= tap0 IPv4 infix-c0-ff-ee SSH Remote Terminal local
hostname = [infix-c0-ff-ee.local]
address = [10.0.1.1]
port = [22]
txt = []
= tap0 IPv6 infix-c0-ff-ee SFTP File Transfer local
hostname = [infix-c0-ff-ee.local]
address = [fe80::ff:fec0:ffed]
port = [22]
txt = []
= tap0 IPv6 infix-c0-ff-ee SSH Remote Terminal local
hostname = [infix-c0-ff-ee.local]
address = [fe80::ff:fec0:ffed]
port = [22]
txt = []
^C
linux-pc:#
Additionally, avahi-resolve-host-name can be used to verify domain name mappings for IP addresses. By default, it translates from IPv4 addresses. This function allows users to confirm that addresses are mapped correctly.
linux-pc:# avahi-resolve-host-name infix-c0-ff-ee.local
infix-c0-ff-ee.local 10.0.1.1
linux-pc:#
Thanks to mDNS we can use the advertised name instead of the IP
address for operations like ping and ssh as shown below:
linux-pc:# ping infix-c0-ff-ee.local -c 3
PING infix-c0-ff-ee.local (10.0.1.1) 56(84) bytes of data.
64 bytes from 10.0.1.1: icmp_seq=1 ttl=64 time=0.852 ms
64 bytes from 10.0.1.1: icmp_seq=2 ttl=64 time=1.12 ms
64 bytes from 10.0.1.1: icmp_seq=3 ttl=64 time=1.35 ms
--- infix-c0-ff-ee.local ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 0.852/1.105/1.348/0.202 ms
linux-pc:# ssh admin@infix-c0-ff-ee.local
(admin@infix-c0-ff-ee.local) Password:
.-------.
| . . | Infix -- a Network Operating System
|-. v .-| https://kernelkit.org
'-'---'-
Run the command 'cli' for interactive OAM
linux-pc:#
To disable mDNS/mDNS-SD, type the commands:
admin@infix-c0-ff-ee:/> configure
admin@infix-c0-ff-ee:/config/> no mdns
admin@infix-c0-ff-ee:/config/> leave
Human-Friendly Hostname Alias
Each Infix unit will advertise itself as infix.local, in addition to its full hostname (e.g., infix-c0-ff-ee.local or foo.local). This alias works seamlessly on a network with a single Infix device, and makes it easy to connect when the exact hostname is not known in advance. The examples below show how the alias can be used for actions such as pinging or establishing an SSH connection:
linux-pc:# ping infix.local -c 3
PING infix.local (10.0.1.1) 56(84) bytes of data.
64 bytes from 10.0.1.1: icmp_seq=1 ttl=64 time=0.751 ms
64 bytes from 10.0.1.1: icmp_seq=2 ttl=64 time=2.28 ms
64 bytes from 10.0.1.1: icmp_seq=3 ttl=64 time=1.42 ms
--- infix.local ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 0.751/1.482/2.281/0.626 ms
linux-pc:# ssh admin@infix.local
(admin@infix.local) Password:
.-------.
| . . | Infix -- a Network Operating System
|-. v .-| https://kernelkit.org
'-'---'-
Run the command 'cli' for interactive OAM
linux-pc:#
When multiple Infix devices are present on the LAN the alias will not uniquely identify a device; infix.local will refer to any of the Infix devices, likely the one that first appeared.
When multiple Infix units are present, use the full hostname (e.g., infix-c0-ff-ee.local or foo.local) rather than the alias infix.local to deterministically connect to a unit.
Netbrowse service to find all your devices
Another mDNS alias that all Infix devices can advertise is network.local. This is a web service which basically runs avahi-browse and displays a table of other Infix devices and their services.
With multiple Infix devices on the LAN, one will be your portal to access all others, if it goes down another will take its place.
To disable the netbrowse service, the following commands can be used:
admin@infix-c0-ff-ee:/> configure
admin@infix-c0-ff-ee:/config/> edit web
admin@infix-c0-ff-ee:/config/web/> no netbrowse
admin@infix-c0-ff-ee:/config/web/> leave
-
lldpd: implementation of IEEE 802.1ab (LLDP) includes lldpcli, which is handy to sniff and display LLDP packets. ↩︎
-
mdns-scan: a tool for scanning for mDNS/DNS-SD published services on the local network ↩︎