Subject: Telecom Network Management

Topic: Internet Management(SNMP)

Difficulty: Medium

Limitations of SNMP v1

i. SNMP has issues with SNMP request handling and with SNMP trap handling in both agents and managers.

ii. In essence, the advisory said what everybody everywhere already knew: that SNMPv1 is insecure and its use can expose system to exploitation.

iii. It further found specific vulnerabilities for a limited set of SNMP agents that could lead to DOS attacks, buffer under run exploits, and other nastiness.

iv. The source of these was found to be in the vendor-specific functions written to parse ASN.1 formatted MIB definitions, but fortunately not in ASN.1 itself.

v. These vulnerabilities were immediately addressed by most vendors and by HP through patches to NNM 6.2 and other HP products.

vi. SNMP PDU size limitations: This is a concern when using data collections. When there are many collections configured, there may be excessive fragmentations attributable to NNM SNMP operations. An implementation of this [SNMP] protocol need not accept messages.

vii. SNMP may not be suitable for the management of truly large networks because of the performance limitations of polling.

viii. SNMP is not well suited for retrieving large volumes of data, such as an entire routing table.

ix. SNMP traps are unacknowledged & may not be delivered.

x. SNMP provides only trivial authentication i.e. it is suitable for monitoring rather than control.

xi. SNMP does not support explicit actions i.e., an action is taken by changing a parameter or setting an object value (indirectly).

xii. SNMP does not support manager-to-manager communications.

• Limited errors codes
• Limited notifications
  • Limited performance
  • Transport dependence
  • Lack of hierarchies
  • Lack of security