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:fe00:0*. ``` 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:fe00:0%tap0: icmp_seq=1 ttl=64 time=0.558 ms 64 bytes from fe80::ff:fe00:0%tap0: icmp_seq=2 ttl=64 time=0.419 ms 64 bytes from fe80::ff:fe00:0%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:fe00:0%tap0 admin@fe80::ff:fe00:0%tap0's password: admin admin@infix-00-00-00:~$ ``` ## Discovery mechanisms available in Infix Infix advertises its presence via the [mDNS](#mdns) and [LLDP](#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 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): 02:00:00:00:00:00 (oui Unknown) Port ID TLV (2), length 7 Subtype MAC address (3): 02:00:00:00:00:00 (oui Unknown) Time to Live TLV (3), length 2: TTL 120s System Name TLV (5), length 14: infix-00-00-00 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:fe00:0 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): 02:00:00:00:00:00 (oui Unknown) Port ID TLV (2), length 7 Subtype MAC address (3): 02:00:00:00:00:00 (oui Unknown) Time to Live TLV (3), length 2: TTL 120s System Name TLV (5), length 14: infix-00-00-00 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:# ``` [^1]: [lldpd: implementation of IEEE 802.1ab (LLDP)](https://github.com/lldp/lldpd) includes *lldpcli*, which is handy to sniff and display LLDP packets. ### 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-scan*[^2] can be used to search for devices advertising their services via mDNS. ``` linux-pc:# avahi-browse -ar + tap0 IPv6 infix-00-00-00 SFTP File Transfer local + tap0 IPv4 infix-00-00-00 SFTP File Transfer local + tap0 IPv6 infix-00-00-00 SSH Remote Terminal local + tap0 IPv4 infix-00-00-00 SSH Remote Terminal local = tap0 IPv4 infix-00-00-00 SFTP File Transfer local hostname = [infix-00-00-00.local] address = [10.0.1.1] port = [22] txt = [] = tap0 IPv4 infix-00-00-00 SSH Remote Terminal local hostname = [infix-00-00-00.local] address = [10.0.1.1] port = [22] txt = [] = tap0 IPv6 infix-00-00-00 SFTP File Transfer local hostname = [infix-00-00-00.local] address = [fe80::ff:fe00:0] port = [22] txt = [] = tap0 IPv6 infix-00-00-00 SSH Remote Terminal local hostname = [infix-00-00-00.local] address = [fe80::ff:fe00:0] port = [22] txt = [] ^C linux-pc:# ``` [^2]: [mdns-scan](http://0pointer.de/lennart/projects/mdns-scan/): a tool for scanning for mDNS/DNS-SD published services on the local network