Cisco Aironet 1562E

Cisco · outdoor 802.11ac Wave 2 access point, external antennas · AIR-AP1562E

what it is

An access point for outdoor use from the Aironet 1560 series, 802.11ac Wave 2. The letter E in the name stands for external antennas. It has two radios — 2.4 GHz and 5 GHz — and one gigabit port. Reading from the device: on 2.4 GHz, 2 × 4 dBi antennas and power up to 16 dBm in five steps; on 5 GHz, 2 × 5 dBi antennas and power up to 24 dBm in eight steps.

It can work under a controller and can itself act as a Mobility Express controller. It is sometimes shipped with a factory Mobility Express image rather than a subordinate access point (CAPWAP) image — and that determines what happens on first connection.

There is no third radio. The 2802, 3802 and 4800 models have three radio slots with a radio switchable between bands; the 1562E has two fixed ones.

channels in the European domain

In the -E (ETSI) variant the 5 GHz radio has only DFS channels: 100, 104, 108, 112, 116, 132, 136 and 140. Channels 36–48 and above 149 are absent — outdoors only the 5470–5725 MHz band with radar detection remains. Consequences:

• Every time the 5 GHz radio comes up it is preceded by radar listening (CAC); the radio then reports DFS scan in process.
• A 5 GHz mesh bridge will not meet indoor access points sitting on channel 36. And on a DFS channel, radar can tear the bridge down.
• A bridge on 2.4 GHz works. Measured: an access point in the root role (RootAP) moved the bridge to channel 11 in the 2.4 GHz band without a restart. Condition: the channel and power of the 2.4 GHz radio set manually, not by the controller's automation.

what we read from it

Through the controller it is connected to:

• channel and width of each radio — including the fact that the 5 GHz radio can do 80 MHz while the controller keeps it at 20 MHz,
• noise floor on every DFS channel and the noise profile assessment,
• Ethernet port state: speed, duplex, traffic and error counters,
• data tunnel response time to the controller,
• CleanAir — spectrum quality and interference events on 2.4 GHz. The sensor starts only once the access point receives its configuration from the controller,
• the full access point log (show ap eventlog) without logging in to the access point itself,
• foreign networks and probing devices heard by the radios.

first connection with a Mobility Express image

An access point with a Mobility Express image in a different version than the controller falls into a join loop roughly every 2 minutes 10 seconds. The access point console shows:

• AC rejected join request[17], try again later.
• Controller rejected image download.Check if TFTP server configured on ME WLC or maximum concurrent download limit has reached
• Image download did not start for 120 seconds.

The message must be read literally: the controller has nowhere to get an image for the access point from. What helped was enabling Auto AP-Type Conversion on the controller and pointing it to an image source. From saving the settings to a working access point took about 9 minutes, without touching the hardware.

Pitfalls of this loop:

• The controller shows the access point as joined (Joined, REGISTERED), although it never receives configuration. Only Configuration requests received: 0 in show ap join stats detailed tells the truth.
• Data from an unfinished join looks truncated: serial number and PID one character shorter, memory 0 KB, regulatory domain Unconfigured. This is not truncation but incomplete data — after a successful join the same controller shows the full values.
• The access point name changes after joining: dots in a name of the form APxxxx.xxxx.xxxx turn into hyphens, and the old name stops working in show ap commands.

bridge mode and monitor mode

Switching to Flex+Bridge mode is blocked by three obstacles, each with a different symptom:

• The bridge radio channel and power must be set manually — otherwise the controller refuses with the message Backhaul channel and TxPower must be in Custom setting.
• The (y/N) prompt swallows the next command. The default answer is "no"; without an answer, the first character of the next command becomes the answer, and the rest goes through as garbage.
• Bridge MAC filter. When the controller requires it, an access point not on the list silently drops out in the configuration phase with the reason AAA authen. The list takes the Ethernet MAC address, not the radio address the controller uses in its log.

Monitor mode is most reliably recognized by N/A(Monitor) in the channel and power columns of show advanced 802.11a summary. show ap monitor-mode summary lists the access point but leaves the state columns empty. Monitor mode adds no new data — SNMP tables and foreign network detection look the same as in normal operation.

console and addresses

• The console runs at 9600 b/s. Before joining a controller the factory credentials work; after joining — the account passed down by the controller.
• An empty Enter uses up a login attempt: it goes past Username: to Password:.
• Roughly every 15 seconds the console prints a CAPWAP line starting with [* — a script looking for the prompt must filter it out.
• Without privileged mode the console has four commands: enable, logout, ping, show. Diagnostic commands — cdp, lldp, mesh, cleanair, logging — are revealed only by enable.
• Two MAC addresses: Ethernet and radio. show ap join stats summary all puts the radio address in the AP EthernetMac column.
• MTU 2400 on the wired port is a correct state — the system raises it for the CAPWAP tunnel.
• A log entry about a failed radio 2 (Init of radio 2 failed!!!!!) is normal: the system tries to start a third radio that this model does not have.

what we cannot read

• The CDP and LLDP neighbor from the access point itself — show cdp neighbors detail and show lldp neighbors detail return % Invalid input, and the controller returns an empty list. The switch port has to be determined on the switch side.
• A switchable radio (802.11-abgn), BLE or hyperlocation — this model does not have them.
• Additional LAN ports — there is one wired port.

full parameter list

A full parameter list for this model is not here yet — the ones described above are those we have read and verified. A missing list does not mean the device exposes nothing more.