# Device Discovery Infix advertises itself via the [mDNS-SD](#mdns-sd) and [LLDP](#lldp) discovery protocols. mDNS-SD has good client support in Windows, macOS and on Linux systems. More on these protocols later. An even simpler method is available when directly attached to an Infix device: ``` .----. Ethernet .--------. | PC +---------------------+ Device | '----' if1 e1 '--------' ``` With IPv6 you can *ping the all-hosts* address (ff02::1), the device's link-local IPv6 address is then seen in the response. In the following example, the PC here uses *tap0* as *if1*, 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:# ``` > [!TIP] > The `-L` option ignores local responses from the PC. This address can then be used to connect to the device, e.g., using SSH. Notice the syntax `username@address%interface`: ``` linux-pc:# ssh admin@fe80::ff:fec0:ffed%tap0 admin@fe80::ff:fec0:ffed%tap0's password: admin admin@infix-c0-ff-ee:~$ ``` ## LLDP Infix supports LLDP (IEEE 802.1AB). For a device with factory default settings, the link-local IPv6 address can be read from the Management Address TLV using *tcpdump* or other sniffing tools[^1]: ``` 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 device 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 following capabilities are available via NETCONF/RESTCONF or the Infix CLI. ### LLDP Enable/Disable 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:/> ``` To reenable it from the CLI config mode: ``` admin@test-00-01-00:/config/> set lldp enabled admin@test-00-01-00:/config/> leave ``` ### LLDP Message Transmission Interval By default, LLDP uses a `message-tx-interval` of 30 seconds, as defined by the IEEE standard. Infix allows this value to be customized. To change it using the CLI: ``` admin@test-00-01-00:/config/> set lldp message-tx-interval 1 admin@test-00-01-00:/config/> leave ``` ### LLDP Administrative Status per Interface Infix supports configuring the LLDP administrative status on a per-port basis. The default mode is `tx-and-rx`, but the following options are also supported: - `rx-only` – Receive LLDP packets only - `tx-only` – Transmit LLDP packets only - `disabled` – Disable LLDP on the interface Example configuration: ``` admin@test-00-01-00:/config/> set lldp port e8 dest-mac-address 01:80:C2:00:00:0E admin-status disabled admin@test-00-01-00:/config/> set lldp port e5 dest-mac-address 01:80:C2:00:00:0E admin-status rx-only admin@test-00-01-00:/config/> set lldp port e6 dest-mac-address 01:80:C2:00:00:0E admin-status tx-only admin@test-00-01-00:/config/> leave ``` > [!NOTE] > The destination MAC address must be the standard LLDP multicast > address: `01:80:C2:00:00:0E`. ### Displaying LLDP Neighbor Information In CLI mode, Infix also provides a convenient `show lldp` command to list LLDP neighbors detected on each interface: ``` admin@test-00-01-00:/> show lldp INTERFACE REM-IDX TIME CHASSIS-ID PORT-ID e5 1 902 00:a0:85:00:04:01 00:a0:85:00:04:07 e6 3 897 00:a0:85:00:03:01 00:a0:85:00:03:07 e8 2 901 00:a0:85:00:02:01 00:a0:85:00:02:05 ``` ## mDNS-SD DNS-SD/mDNS-SD can be used to discover Infix devices and services. By default, Infix use the `.local` domain for advertising services. Some networks use `.lan` instead, so this configurable: ``` admin@infix-c0-ff-ee:/> configure admin@infix-c0-ff-ee:/config/> edit mdns admin@infix-c0-ff-ee:/config/mdns/> set domain lan ``` Other available settings include limiting the interfaces mDNS responder acts on: ``` admin@infix-c0-ff-ee:/config/> set interfaces allow e1 ``` or ``` admin@infix-c0-ff-ee:/config/> set interfaces deny wan ``` The `allow` and `deny` settings are complementary, `deny` always wins. ---- In Linux, tools such as *avahi-browse* or *mdns-scan*[^2] 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:# ``` > [!TIP] > The `-t` option is also very useful, it stops browsing automatically > when a "more or less complete list" has been printed. However, some > devices on the LAN may be in deep sleep so run the command again if > you cannot find the device you are looking for. 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 OS — Immutable.Friendly.Secure |-. 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 deviuce 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 OS — Immutable.Friendly.Secure |-. v .-| https://kernelkit.org '-'---'- Run the command 'cli' for interactive OAM admin@infix-c0-ff-ee:~$ ``` 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. > [!NOTE] > When multiple Infix devices are present on the LAN, use the full name, > e.g., *infix-c0-ff-ee.local* or *foo.local* rather than the alias > *infix.local* to deterministically connect to the device. ### Browse Network Using *network.local* Another mDNS alias that all Infix devices 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. ![Netbrowse Service - network.local](img/network-local.png) With multiple Infix devices on the LAN, one will take the role of your portal to access all others, if it goes down another takes its place. To disable the netbrowse service, and the *network.local* alias, 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 ``` [^1]: E.g., [lldpd](https://github.com/lldp/lldpd) which includes the *lldpcli* too, handy to sniff and display LLDP packets. [^2]: [mdns-scan](http://0pointer.de/lennart/projects/mdns-scan/): a tool for scanning for mDNS/DNS-SD services on the local network.