Juniper IP SERVICES - CONFIGURATION GUIDE V 11.1.X, Configuration Manual

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Figure 21: Tunneling Through an IP Network That Fragments Packets
Platform Considerations
For information about modules that support IP reassembly on the ERX7xx models,
ERX14xx models, and the ERX310 Broadband Services Router:
■
See ERX Module Guide, Table 1, Module Combinations for detailed module
specifications.
■
See ERX Module Guide, Appendix A, Module Protocol Support for information about
the modules that support IP reassembly.
For information about modules that support IP reassembly on the E120 or E320
Broadband Services Router:
■
See E120 and E320 Module Guide, Table 1, Modules and IOAs for detailed module
specifications.
■
See E120 and E320 Module Guide, Appendix A, IOA Protocol Support for information
about the modules that support IP reassembly.
Module Requirements
The types of modules that support IP reassembly for tunnel packets depend on the
type of E Series router that you have.
ERX7xx Models, ERX14xx Models, and the ERX310 Router
To configure IP reassembly on ERX7xx models, ERX14xx models, and the ERX310
router, you must install one of a Service Module (SM), an IPSec Service line module
(ISM), or a module that supports the use of shared tunnel-server ports. With these
modules, an ERX router can perform reassembly of IP packets that it receives on
DVMRP, GRE, IPSec, and L2TP tunnels.
Because IP reassembly is required only on tunnel egress packets, the router performs
reassembly only on packets in which the IP destination address is local to the router
and in which the underlying protocol is one of the supported tunneling protocols.
SMs provide dedicated tunnel-server ports that are always configured on the module.
Unlike other line modules, SMs, and ISMs do not pair with corresponding I/O modules
that contain ingress and egress ports. Instead, they receive data from and transmit
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Platform Considerations
JUNOSe 11.1.x IP Services Configuration Guide