With IPHost Network Monitor you can run simple snmp requests against a Alcatel device in your network.
vlanMtu
vlan Mtu
1.3.6.1.4.1.52.4.12.30.1.12.1.1.22
Maximum transmission unit i.e. the maximum size of packet that this vlan can handle. It ranges from 512 to 1500 (for Hawk) and 10222(for Falcon and Eagle)
Back to ALCATEL-IND1-VLAN-MGR-MIB MIB page.
IPHost Network monitor allows you to monitor vlanMtu on Alcatel device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Alcatel IP phones right now.
