ae: Aggregated Ethernet A virtual aggregated link.
as: Aggregated SONET/SDH A virtual aggregated link.
at: ATM1 or ATM2 IQ Asynchronous Transfer Mode
cau4: Channelized AU-4 IQ Configured on the Channelized STM-1 IQ PIC.
coc1: Channelized OC-1 IQ Configured on the Channelized OC-12 IQ PIC.
coc12: Channelized OC-12 IQ Configured on the Channelized OC-12 IQ PIC.
cstm1: Channelized STM-1 IQ Configured on the Channelized STM-1 IQ PIC.
ce1: Channelized E1 IQ Configured on the Channelized E1 IQ PIC or Channelized
STM-1 IQ PIC.
ct1: Channelized T1 IQ Configured on the Channelized DS-3 IQ PIC or
Channelized OC-12 IQ PIC.
ct3: Channelized T3 IQ Configured on the Channelized DS-3 IQ PIC or
Channelized OC-12 IQ PIC.
cp: Collector Configured on the Monitoring Services II PIC.
ds: DS-0 Configured on the Channelized DS-3 to DS-0 PIC, Channelized E1 PIC, Channelized OC-12 IQ PIC
dsc: Discard Allows you to identify the ingress point of a denial-of-service (DoS) attack.
e1: E1 Includes the channelized STM-1 to E1 interfaces.
e3: E3 Includes the E3 IQ interfaces.
es: Encryption Allows you to configure a security association (SA) name
with a logical interface.
fe: Fast Ethernet 100Base-TX (Fast Ethernet, 100 Mbps).
fxp0: Management and internal Ethernet The management Ethernet interface is an out-of-bandmanagement interface within the routing platform.
fxp1: Interface that connects the routing engine and packet forwarding engine.
ge: Gigabit Ethernet Includes Gigabit Ethernet IQ interfaces.
gr: Generic Route Encapsulation tunnel Allows you to configure a unicast tunnel using GRE
encapsulation.
gre: Internally generated This interface is internally generated and is not
configurable.
ip: IP-over-IP encapsulation tunnel Allows you to configure a unicast tunnel using IP-IP
encapsulation.
ipip: Internally generated This interface is internally generated and is not
configurable.
lo Loopback This interface is internally generated. The logical
interface lo0.16383 is a non-configurable interface for routing platform control traffic.
ls: Link services Supports bundles that contain links.
lsi: Internally generated This interface is internally generated and is not
configurable.
ml: Multilink Includes Multilink Frame Relay and Multilink PPP.
mo: Monitoring services Includes the monitoring services and monitoring services
II interfaces. The logical interface mo-fpc/pic/port.16383 is an internally generated, non-configurable interface for routing platform control traffic.
mt: Multicast tunnel Internal routing platform interface for VPNs.
mtun: Internally generated This interface is internally generated and is not
configurable.
me0: – out of band management interface on ex switches
oc3: OC-3 IQ Configured on the Channelized OC-12 IQ PIC.
pe: This interface is present on the first-hop routing platform. Encapsulates packets destined for the rendezvous point (RP) routing platform.
pd: This interface is present on the RP De-encapsulates packets at the RP.
pimd: Internally generated This interface is internally generated and is not
configurable.
pime: Internally generated This interface is internally generated and is not
configurable.
rlsq: – a redundant bundle interface, made of two or more lsq interface. If you have redundant AS Pics.
se: Serial Includes the EIA-530, V.35, and X.21 interfaces.
so: SONET/SDH Both are widely used methods for very high speed
transmission of voice and data signals across the numerous world-wide fiber-optic networks.
sp: Adaptive services The logical interface sp-fpc/pic/port.16383 is an
internally generated, non-configurable interface for routing platform control traffic.
t1: T1 Includes the channelized DS-3 to DS-1 interfaces.
t3: T3 Includes the channelized OC-12 to DS-3 interfaces.
tap: Internally generated This interface is internally generated and is not
configurable.
vcp: – virtual chassis interface (EX4200 only)
vsp: Voice services The Adaptive Services (AS) Physical Interface Card (PIC)
supports the compressed real-time transport protocol (RTP) on this interface.
vt: Virtual loopback tunnel On routing platforms equipped with a Tunnel PIC,
enables egress filtering.
xe: – 1GE optical interface on ex switches

Juniper reference:
http://www.juniper.net/techpubs/software/nog/nog-interfaces/download/nog-interfaces.pdf

You can configure the router or an interface to act as a Dynamic Host Configuration Protocol (DHCP) or Bootstrap Protocol (BOOTP) relay agent. This means that a locally attached host can issue a DHCP or BOOTP request as a broadcast message. If the router or an interface sees this broadcast message, it relays the message to a specified DHCP or BOOTP server.

You should configure the router or an interface to be a DHCP/BOOTP relay agent if you have locally attached hosts and a distant DHCP or BOOTP server.

To configure the router to act as a DHCP/BOOTP relay agent, include the bootp statement at the [edit forwarding-options helpers] hierarchy level:

[edit forwarding-options helpers]

bootp {

description description-of-service;

interface interface-group {

description description-of-interface;

maximum-hop-count number;

minimum-wait-time seconds;

no-listen;

server [ addresses ];

}

maximum-hop-count number;

minimum-wait-time seconds;

server [ addresses ];

To set the description of the BOOTP service, DHCP service, or interface, include the description statement.

To set a logical interface or a group of logical interfaces with a specific DHCP-relay or BOOTP configuration, include the interface statement.

To set the routing instance of the server to forward, include the routing-instance statement. You can include as many routing instances as necessary in the same statement.

To stop packets from being forwarded on a logical interface, a group of logical interfaces, or the router, include the no-listen statement.

To set the maximum allowed number in the hops field of the BOOTP header, include the maximum-hop-count statement. Headers that have a larger number in the hops field are not forwarded. If you omit the maximum-hop-count statement, the default value is 4 hops.

To set the minimum allowed number of seconds in the secs field of the BOOTP header, include the minimum-wait-time statement. Headers that have a smaller number in the secs field are not forwarded. If you omit the minimum-wait-time statement, the default value is 3 seconds.

To set the IP address or addresses that specify the DHCP or BOOTP server for the router or interface, include the server statement. You can include as many addresses as necessary in the same statement.

You can also configure an individual logical interface to be a DHCP/BOOTP relay if you have locally attached hosts and a remote DHCP or BOOTP server at the [edit interfaces] hierarchy level. For more information, see the JUNOS Class of Service Configuration Guide.

To stop recording system messages :

deactivate system syslog file messages

and to start recording :

activate system syslog file messages

To turn of logging :

delete system syslog file messages